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#1
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HELP - Please Identify These Two Parts....................
EADGBE schrieb:
Actually, I'll do just a bit better. Here are ALL of the circuit board traces, done as best as I can. Let me know if the traces aren't clear enough: http://i240.photobucket.com/albums/f...23/CIRCUIT.jpg By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. Obviously, you've forgotten the red connection: http://www.bilder-hochladen.net/files/12b4-2t-jpg.html HTH Reinhard |
#2
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HELP - Please Identify These Two Parts....................
I have a "rainy afternoon project" that has got me puzzled. I have an old Pioneer cassette deck that I am restoring. The capstan motor worked for a short while, then it stopped. The casing of the motor felt VERY warm, so I knew something was amiss. (One of the voltage regulators in the deck's main power supply became EXTREMELY hot whenever the capstan motor was connected, which was another clue). Suspecting a short in the capstan motor, I took the motor apart. Take a look at what I found when I examined the motor's internal voltage regulator circuit board... http://i240.photobucket.com/albums/f...3/SCORCHED.jpg The motor's voltage regulator had burned itself up. Look at how scorched the circuit board is! I have a replacement regulator, but I want to make sure that all is well inside this circuit before installing the replacement. (Yes, I KNOW that I could simply get another motor, but remember, I am tinkering for the sake of tinkering!) So I have been checking all of the other components in this circuit, to verify their health. The one component that has me puzzled is the small black "diode" indicated at the bottom of the photo. There is no mark on this component other than the yellow stripe you see. I cannot get any type of reading on this component when I use my multimeter -- I get nothing using my diode check function (forward or reverse bias), no continuity, no resistance reading. It must be faulty, I am assuming. The other component that has me puzzled is the olive green "resistor" just above the larger blue electrolytic capacitor. I get a steady resistance reading of .5 ohms on this component. I am going to disconnect at least one leg of each of these two "mystery components" and take further readings, but I'm not used to getting such odd readings right off the bat on these two components. Can anyone provide any clues as to what these components are? BY THE WAY, the motor is fed a steady voltage of 12.5 volts DC, with no AC voltage ripple present. I have verified this. Thanks In Advance..... |
#3
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HELP - Please Identify These Two Parts....................
EADGBE wrote in message
... I have a "rainy afternoon project" that has got me puzzled. I have an old Pioneer cassette deck that I am restoring. The capstan motor worked for a short while, then it stopped. The casing of the motor felt VERY warm, so I knew something was amiss. (One of the voltage regulators in the deck's main power supply became EXTREMELY hot whenever the capstan motor was connected, which was another clue). Suspecting a short in the capstan motor, I took the motor apart. Take a look at what I found when I examined the motor's internal voltage regulator circuit board... http://i240.photobucket.com/albums/f...3/SCORCHED.jpg The motor's voltage regulator had burned itself up. Look at how scorched the circuit board is! I have a replacement regulator, but I want to make sure that all is well inside this circuit before installing the replacement. (Yes, I KNOW that I could simply get another motor, but remember, I am tinkering for the sake of tinkering!) So I have been checking all of the other components in this circuit, to verify their health. The one component that has me puzzled is the small black "diode" indicated at the bottom of the photo. There is no mark on this component other than the yellow stripe you see. I cannot get any type of reading on this component when I use my multimeter -- I get nothing using my diode check function (forward or reverse bias), no continuity, no resistance reading. It must be faulty, I am assuming. The other component that has me puzzled is the olive green "resistor" just above the larger blue electrolytic capacitor. I get a steady resistance reading of .5 ohms on this component. I am going to disconnect at least one leg of each of these two "mystery components" and take further readings, but I'm not used to getting such odd readings right off the bat on these two components. Can anyone provide any clues as to what these components are? BY THE WAY, the motor is fed a steady voltage of 12.5 volts DC, with no AC voltage ripple present. I have verified this. Thanks In Advance..... Is the diode oriented to soak up back emfs from the motor ? The green thing is an inductor -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
#4
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HELP - Please Identify These Two Parts....................
EADGBE wrote:
I have a "rainy afternoon project" that has got me puzzled. I have an old Pioneer cassette deck that I am restoring. The capstan motor worked for a short while, then it stopped. The casing of the motor felt VERY warm, so I knew something was amiss. (One of the voltage regulators in the deck's main power supply became EXTREMELY hot whenever the capstan motor was connected, which was another clue). Suspecting a short in the capstan motor, I took the motor apart. Take a look at what I found when I examined the motor's internal voltage regulator circuit board... http://i240.photobucket.com/albums/f...3/SCORCHED.jpg The motor's voltage regulator had burned itself up. Look at how scorched the circuit board is! I have a replacement regulator, but I want to make sure that all is well inside this circuit before installing the replacement. (Yes, I KNOW that I could simply get another motor, but remember, I am tinkering for the sake of tinkering!) So I have been checking all of the other components in this circuit, to verify their health. The one component that has me puzzled is the small black "diode" indicated at the bottom of the photo. There is no mark on this component other than the yellow stripe you see. I cannot get any type of reading on this component when I use my multimeter -- I get nothing using my diode check function (forward or reverse bias), no continuity, no resistance reading. It must be faulty, I am assuming. The other component that has me puzzled is the olive green "resistor" just above the larger blue electrolytic capacitor. I get a steady resistance reading of .5 ohms on this component. I am going to disconnect at least one leg of each of these two "mystery components" and take further readings, but I'm not used to getting such odd readings right off the bat on these two components. Can anyone provide any clues as to what these components are? BY THE WAY, the motor is fed a steady voltage of 12.5 volts DC, with no AC voltage ripple present. I have verified this. Thanks In Advance..... Well, I guess you now know why the reg burt up. that diode is suppose to go across the motor leads to suppress back EMF which can damage components.. It would be a simply low current SI diode. http://webpages.charter.net/jamie_5" |
#5
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HELP - Please Identify These Two Parts....................
The anode of the diode is attached directly to three of the resistors
as shown. I have tried to re-create the circuit board traces on the other side. The cathode connects to what N_Cook has described as an inductor. Take a look at this photo: http://i240.photobucket.com/albums/f...e123/DIODE.jpg Thanks to everyone for your help so far. Any chance of finding a replacement for this diode? |
#6
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HELP - Please Identify These Two Parts....................
Actually, I'll do just a bit better.
Here are ALL of the circuit board traces, done as best as I can. Let me know if the traces aren't clear enough: http://i240.photobucket.com/albums/f...23/CIRCUIT.jpg By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. |
#7
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HELP - Please Identify These Two Parts....................
On Sun, 5 Oct 2008 17:48:53 -0700 (PDT), EADGBE
wrote: Actually, I'll do just a bit better. Here are ALL of the circuit board traces, done as best as I can. Let me know if the traces aren't clear enough: http://i240.photobucket.com/albums/f...23/CIRCUIT.jpg By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. WHere does the motor winding itself attach? I'm guessing that the pins on the 'bottom' of the image are teh power input, right? |
#8
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HELP - Please Identify These Two Parts....................
"EADGBE" wrote...
The one component that has me puzzled is the small black "diode" indicated at the bottom of the photo. There is no mark on this component other than the yellow stripe you see. I cannot get any type of reading on this component when I use my multimeter -- I get nothing using my diode check function (forward or reverse bias), no continuity, no resistance reading. It must be faulty, I am assuming. So are you saying that the resistance is "infinite" regardless of how you try to measure it? If that is the case, then it is likely "blown". Dunno how critical it is without the full schematic diagram. If it IS blown, then you should likely discover WHY before replacing it or the replacement may blow instantly as well. The other component that has me puzzled is the olive green "resistor" just above the larger blue electrolytic capacitor. I get a steady resistance reading of .5 ohms on this component. Do you have some reason to believe that it is not just a 0.5 ohm resistor? Again, hard to guess without the full schematic diagram. |
#9
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HELP - Please Identify These Two Parts....................
"EADGBE" wrote ...
The anode of the diode is attached directly to three of the resistors as shown. I have tried to re-create the circuit board traces on the other side. The cathode connects to what N_Cook has described as an inductor. Take a look at this photo: http://i240.photobucket.com/albums/f...e123/DIODE.jpg Thanks to everyone for your help so far. Any chance of finding a replacement for this diode? Depending on what the actual diagram looks like, it is quite possibly a simple, generic silicon diode like a 1N4001 (power rectifier) or maybe even a popular signal diode like a 1N4148, etc. These are both very common parts that likely cost only a few cents in production quantities. |
#10
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HELP - Please Identify These Two Parts....................
"EADGBE" wrote ...
Actually, I'll do just a bit better. Here are ALL of the circuit board traces, done as best as I can. Let me know if the traces aren't clear enough: http://i240.photobucket.com/albums/f...23/CIRCUIT.jpg That is good, but you don't indicate which nodes connect to the motor, and which are the power input (+ and -). Without that critical info, it won;t be easy to make much sense out of the circuit. By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. Are you SURE you have a replacement for this IC? Panasonic lists it as an "application specific circuit" (i.e. a custom-made chip, not a generic part). And it says that it is "obsolete" (i.e. not made anymore). Also there is no indication that it is a "regulator", or that it has any replacement. http://industrial.panasonic.com/www-...5+AN6601N+8+WW Furthermore, the original was so burned up (as shown by your excellent photo), that I would be reluctant to just replace it without determining WHAT caused the original to burn. I don't remember that you revealed anything about the motor itself (impedances?, windings?, brushes? mechanical rotation? etc.) |
#11
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HELP - Please Identify These Two Parts....................
On Sun, 5 Oct 2008 17:48:53 -0700 (PDT), EADGBE
put finger to keyboard and composed: Actually, I'll do just a bit better. Here are ALL of the circuit board traces, done as best as I can. Let me know if the traces aren't clear enough: http://i240.photobucket.com/albums/f...23/CIRCUIT.jpg By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. My vrt databook lists the TDA1151 and TDA1152 as equivalents for the AN6610. Here is a datasheet and application circuits for the TDA1151: http://www.datasheetarchive.com/pdf-...DSA-633666.pdf This is an equivalent NTE part: http://www.nteinc.com/specs/7000to7099/pdf/nte7089.pdf BTW, I think there is an error in your circuit diagram. AFAICT, there is no DC current path from the IC's output pin and the negative terminal of the motor. As for the motor, I would clean out any carbon dust from between the commutator segments. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#12
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HELP - Please Identify These Two Parts....................
OK, here is the circuit again, this time with positive and negative power inputs labeled.... http://i240.photobucket.com/albums/f.../CIRCUIT_2.jpg |
#13
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HELP - Please Identify These Two Parts....................
I should point something out that I haven't mentioned before... There are two slots in the circuit board. One of them is just above the smaller black electrolytic capacitor, and the other slot is just below the larger blue electrolytic capacitor. You can see the traces going to these slots and appearing to "stop dead". These slots are where the motor contacts are soldered. |
#14
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HELP - Please Identify These Two Parts....................
"Franc Zabkar" wrote ...
EADGBE composed: By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. My vrt databook lists the TDA1151 and TDA1152 as equivalents for the AN6610. Which themselves are listed as "obsolete, discontinued, or hard-to-find". IMHO, doesn't seem worth the effort for an 87-cent motor. YMMV |
#15
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HELP - Please Identify These Two Parts....................
"EADGBE" wrote...
I should point something out that I haven't mentioned before... There are two slots in the circuit board. One of them is just above the smaller black electrolytic capacitor, and the other slot is just below the larger blue electrolytic capacitor. You can see the traces going to these slots and appearing to "stop dead". These slots are where the motor contacts are soldered. Then it appears that you didn't trace the circuit properly. According to your green lines, the only path from the upper motor node is through the adjustable resistor at the top (highly unlikely for such a high impedance as 5000 ohms) or through the black electrolytic capacitor (electrically impossible). How about just posting a photo of the BACK of the board instead of trying to interpret it? There IS a direct path from the +power input to the lower motor node, which seems consistent with the motor speed regulator IC circuit. Did you say that you *have* a replacement for the semiconductor in hand, or that you had simply identified it? |
#16
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HELP - Please Identify These Two Parts....................
On Sun, 5 Oct 2008 20:56:11 -0700, "Richard Crowley"
put finger to keyboard and composed: "Franc Zabkar" wrote ... EADGBE composed: By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. My vrt databook lists the TDA1151 and TDA1152 as equivalents for the AN6610. Which themselves are listed as "obsolete, discontinued, or hard-to-find". IMHO, doesn't seem worth the effort for an 87-cent motor. YMMV I can buy the AN6610 here in Australia for AU$2.75. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#17
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HELP - Please Identify These Two Parts....................
"Franc Zabkar" wrote ...
"Richard Crowley" composed: "Franc Zabkar" wrote ... EADGBE composed: By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. My vrt databook lists the TDA1151 and TDA1152 as equivalents for the AN6610. Which themselves are listed as "obsolete, discontinued, or hard-to-find". IMHO, doesn't seem worth the effort for an 87-cent motor. YMMV I can buy the AN6610 here in Australia for AU$2.75. OK, then that would mean paying AU$2.75 to repair a motor that likely isn't worth half that. Not to mention that without knowing why the original blew, the OP has an excellent chance of blowing up the replacement instantly. That doesn't make sense up here in the Northern Hemisphere. Perhaps things look different from your perspective. :-) |
#18
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HELP - Please Identify These Two Parts....................
In article ,
"Richard Crowley" wrote: "EADGBE" wrote ... The anode of the diode is attached directly to three of the resistors as shown. I have tried to re-create the circuit board traces on the other side. The cathode connects to what N_Cook has described as an inductor. Take a look at this photo: http://i240.photobucket.com/albums/f...e123/DIODE.jpg Thanks to everyone for your help so far. Any chance of finding a replacement for this diode? Depending on what the actual diagram looks like, it is quite possibly a simple, generic silicon diode like a 1N4001 (power rectifier) or maybe even a popular signal diode like a 1N4148, etc. These are both very common parts that likely cost only a few cents in production quantities. I believe it takes at least two transistors. It's a positive feedback system to compensate for losses in the motor, creating a virtual perfect motor that doesn't change speeds under load. And that brings about the second problem... The circuit has only one pot so it's not going to work on a worn motor. The loss compensation is a fixed resistor so it's only good for a motor in perfect condition. -- Google is a pro-spamming service. I will not see your reply if you use Google. |
#19
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HELP - Please Identify These Two Parts....- The motor itself
Hello,
Don't forget the motor itself Only one person mentioned in passing that you should check the actual motor. This is really critical. It is common for the motor itself to be drawing WAY too much current because of brush dust contamination and maybe a seized bearing. Try powering the motor directly (no board) off a 6 volt or so power supply with an amp meter in the line. Unloaded I'd think it should draw well under 100mA in current. The motor being in trouble is what probably caused the IC to run way to hot to begin with. Regards, Tim Schwartz Bristol Electronics EADGBE wrote: I have a "rainy afternoon project" that has got me puzzled. I have an old Pioneer cassette deck that I am restoring. The capstan motor worked for a short while, then it stopped. The casing of the motor felt VERY warm, so I knew something was amiss. (One of the voltage regulators in the deck's main power supply became EXTREMELY hot whenever the capstan motor was connected, which was another clue). Suspecting a short in the capstan motor, I took the motor apart. Take a look at what I found when I examined the motor's internal voltage regulator circuit board... http://i240.photobucket.com/albums/f...3/SCORCHED.jpg The motor's voltage regulator had burned itself up. Look at how scorched the circuit board is! I have a replacement regulator, but I want to make sure that all is well inside this circuit before installing the replacement. (Yes, I KNOW that I could simply get another motor, but remember, I am tinkering for the sake of tinkering!) So I have been checking all of the other components in this circuit, to verify their health. The one component that has me puzzled is the small black "diode" indicated at the bottom of the photo. There is no mark on this component other than the yellow stripe you see. I cannot get any type of reading on this component when I use my multimeter -- I get nothing using my diode check function (forward or reverse bias), no continuity, no resistance reading. It must be faulty, I am assuming. The other component that has me puzzled is the olive green "resistor" just above the larger blue electrolytic capacitor. I get a steady resistance reading of .5 ohms on this component. I am going to disconnect at least one leg of each of these two "mystery components" and take further readings, but I'm not used to getting such odd readings right off the bat on these two components. Can anyone provide any clues as to what these components are? BY THE WAY, the motor is fed a steady voltage of 12.5 volts DC, with no AC voltage ripple present. I have verified this. Thanks In Advance..... |
#20
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HELP - Please Identify These Two Parts....- The motor itself
Richard:
Per your request, I have taken a photo of the back of the circuit board. http://i240.photobucket.com/albums/f.../CIRCUIT_3.jpg I have numbered all of the connections so that no one will get "lost". They are as follows: 1 - speed control pot connections 2 - 43k resistor 3 - 332 ohm(?) resistor (orange/orange/red?/black/brown) 4 - 421M ohm(?) resistor (yellow/red/orange?/blue/green?) 5 - inductor (olive "resistor" shaped part) 6a - negative lead of 10uF/25v electrolytic 6b - positive lead of 10uF/25v electrolytic 7a - negative lead of 3.3uF/25v electrolytic 7b - positive lead of 3.3uF/25v electrolytic 8 - pink "resistor" (red/red/brown/grey/black) 9 - 22 ohm green resistor (red/red/black/silver) 10a - cathode of black diode (yellow stripe is closest to this connection) 10b - anode of black diode The positive and negative power connections are also indicated. SOME QUICK ADDITIONAL COMMENTS, based on comments I have received so far.... REMINDER: I know that I could easily get another motor. I AM SIMPLY TINKERING FOR THE SAKE OF TINKERING, and it's a good opportunity to learn a bit about this circuit. That's all! Someone said that they found a substitute for AN6610, but that is NOT the part number. The burned part says "AN6601". It is made by Matsu****a (Panasonic). I do indeed have an exact replacement for this part in hand. I found it online at a supplier specializing in obsolete semiconductors. I have tested the motor by running 9 volts directly into it. The motor runs smoothly and quietly. I will take a current reading, just to see what I find. But the motor appears to be OK. I am currently going on the assumption that AN6601 failed on its own and/or because of the fault of the diode. |
#21
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HELP - Please Identify These Two Parts....................
"Kevin McMurtrie" wrote ...
"Richard Crowley" wrote: "EADGBE" wrote ... The anode of the diode is attached directly to three of the resistors as shown. I have tried to re-create the circuit board traces on the other side. The cathode connects to what N_Cook has described as an inductor. Take a look at this photo: http://i240.photobucket.com/albums/f...e123/DIODE.jpg Thanks to everyone for your help so far. Any chance of finding a replacement for this diode? Depending on what the actual diagram looks like, it is quite possibly a simple, generic silicon diode like a 1N4001 (power rectifier) or maybe even a popular signal diode like a 1N4148, etc. These are both very common parts that likely cost only a few cents in production quantities. I believe it takes at least two transistors. It's a positive feedback system to compensate for losses in the motor, creating a virtual perfect motor that doesn't change speeds under load. And that brings about the second problem... It *has* likely several transistiors inside the TO-92 plastic package that burned up. Refer to the diagram for the cited integrated circuit. The circuit has only one pot so it's not going to work on a worn motor. The loss compensation is a fixed resistor so it's only good for a motor in perfect condition. It doesn't need more than one pot. The regulator compensates for the variations in the motor. Refer to the diagram for the cited integrated circuit. Google is a pro-spamming service. Agreed. I will not see your reply if you use Google. Since the OP is posting from Google, you will have a hard time following this discussion. |
#22
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HELP - Please Identify These Two Parts....- The motor itself
EADGBE wrote:
snip I do indeed have an exact replacement for this part in hand. I found it online at a supplier specializing in obsolete semiconductors. Please reveal your source; I have had _no_ luck finding obsolete parts houses that sell ICs in small quantities. Michael |
#23
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HELP - Please Identify These Two Parts....................
On Sun, 5 Oct 2008 22:29:42 -0700, "Richard Crowley"
put finger to keyboard and composed: "Franc Zabkar" wrote ... "Richard Crowley" composed: "Franc Zabkar" wrote ... EADGBE composed: By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. My vrt databook lists the TDA1151 and TDA1152 as equivalents for the AN6610. Which themselves are listed as "obsolete, discontinued, or hard-to-find". IMHO, doesn't seem worth the effort for an 87-cent motor. YMMV I can buy the AN6610 here in Australia for AU$2.75. OK, then that would mean paying AU$2.75 to repair a motor that likely isn't worth half that. Not to mention that without knowing why the original blew, the OP has an excellent chance of blowing up the replacement instantly. That doesn't make sense up here in the Northern Hemisphere. Perhaps things look different from your perspective. :-) I just realised the OP's IC is an AN6601, whereas I've been looking for an AN6610. smacks forehead Anyway, if the motor is an odd type, or if the pulley is difficult to remove, then it may make sense to try to repair the PCB. I remember having to do this one time, although I had to make my own PCB, using a different IC, and mounted externally. My effort wasn't wasted, though, as I treated it as a learning experience. BTW, over here audio motors typically cost AU$8.65, which is still cheap. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#24
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HELP - Please Identify These Two Parts....................
On Sun, 05 Oct 2008 23:30:36 -0700, Kevin McMurtrie
put finger to keyboard and composed: In article , "Richard Crowley" wrote: "EADGBE" wrote ... The anode of the diode is attached directly to three of the resistors as shown. I have tried to re-create the circuit board traces on the other side. The cathode connects to what N_Cook has described as an inductor. Take a look at this photo: http://i240.photobucket.com/albums/f...e123/DIODE.jpg Thanks to everyone for your help so far. Any chance of finding a replacement for this diode? Depending on what the actual diagram looks like, it is quite possibly a simple, generic silicon diode like a 1N4001 (power rectifier) or maybe even a popular signal diode like a 1N4148, etc. These are both very common parts that likely cost only a few cents in production quantities. I believe it takes at least two transistors. It's a positive feedback system to compensate for losses in the motor, creating a virtual perfect motor that doesn't change speeds under load. And that brings about the second problem... The circuit has only one pot so it's not going to work on a worn motor. The loss compensation is a fixed resistor so it's only good for a motor in perfect condition. My understanding is that a real motor can be represented as a perfect motor with a small series resistance. To maintain a constant speed under all load conditions, one needs to add an external series resistor of equal value and then add the voltage drop across this resistor to the motor voltage. o---- Rloss ----- perfect motor -----o o--- Rext ---o |--- voltage at motor terminals ---| |-- loss --| Here is a circuit I found in "303 Circuits" by Micro-Tech/Elektor Electronics. |-------------------------| | | | |\ | | | \ | |---|- \ | Vm - Im | \ -----|--- R3 ---|----o o--- MOTOR ---o GND V1 o--- R1 ---|---|+ / | | | / | | |/ | | | |------ R2 ----| Vm = V1 + Im x [(R2/R1) x R3] Effectively you have a voltage source with a negative output resistance of R3 x (R2/R1). - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#25
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HELP - Please Identify These Two Parts....................
On Oct 4, 3:32*am, Reinhard Zwirner wrote:
Obviously, you've forgotten the red connection: http://www.bilder-hochladen.net/files/12b4-2t-jpg.html Reinhard: You are 100 percent correct. My mistake! Thank you for pointing that out. |
#26
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HELP - Please Identify These Two Parts....- The motor itself
On Mon, 6 Oct 2008 06:56:38 -0700 (PDT), EADGBE
put finger to keyboard and composed: Richard: Per your request, I have taken a photo of the back of the circuit board. http://i240.photobucket.com/albums/f.../CIRCUIT_3.jpg I have numbered all of the connections so that no one will get "lost". They are as follows: 1 - speed control pot connections 2 - 43k resistor 3 - 332 ohm(?) resistor (orange/orange/red?/black/brown) 4 - 421M ohm(?) resistor (yellow/red/orange?/blue/green?) 5 - inductor (olive "resistor" shaped part) 6a - negative lead of 10uF/25v electrolytic 6b - positive lead of 10uF/25v electrolytic 7a - negative lead of 3.3uF/25v electrolytic 7b - positive lead of 3.3uF/25v electrolytic 8 - pink "resistor" (red/red/brown/grey/black) 9 - 22 ohm green resistor (red/red/black/silver) 10a - cathode of black diode (yellow stripe is closest to this connection) 10b - anode of black diode The positive and negative power connections are also indicated. SOME QUICK ADDITIONAL COMMENTS, based on comments I have received so far.... REMINDER: I know that I could easily get another motor. I AM SIMPLY TINKERING FOR THE SAKE OF TINKERING, and it's a good opportunity to learn a bit about this circuit. That's all! Someone said that they found a substitute for AN6610, but that is NOT the part number. Sorry, my mistake. The burned part says "AN6601". It is made by Matsu****a (Panasonic). I do indeed have an exact replacement for this part in hand. I found it online at a supplier specializing in obsolete semiconductors. I have tested the motor by running 9 volts directly into it. The motor runs smoothly and quietly. I will take a current reading, just to see what I find. But the motor appears to be OK. I am currently going on the assumption that AN6601 failed on its own and/or because of the fault of the diode. This is how I see your circuit: + o--------|-----|-----|---------| 12V | | | ___|___ | | | | | | | | R4 R2 43K +_|_ | | |_____| C6 ___ | | | D10 10uF | | | |-------||--- L5 --|-----| 25V | | | | | | | R8 Motor R3 3K3 +_|_ | | 220R| | | C7 ___ | | | | |- VR1 5K 3.3uF | | | | | |----| 25V | | | |_____|_________|___________________| | | | | | | voltage | | | feedback | | AN6601 --------------------------------| | | 0V 22uH | | - o-- L9 --|-----------| AFAICT, the AN6601 IC senses the motor voltage via the potential divider consisting of VR1, R2, R3, and R4. I suspect that if this voltage begins to increase, then D10 conducts, causing the voltage at the AN6601's control pin to rise with respect to its supply pin, thus turning off the AN6601 and reducing the motor current. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#27
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HELP - Please Identify These Two Parts....................
EADGBE wrote: I have a "rainy afternoon project" that has got me puzzled. I have an old Pioneer cassette deck that I am restoring. The capstan motor worked for a short while, then it stopped. The casing of the motor felt VERY warm, so I knew something was amiss. (One of the voltage regulators in the deck's main power supply became EXTREMELY hot whenever the capstan motor was connected, which was another clue). Suspecting a short in the capstan motor, I took the motor apart. Take a look at what I found when I examined the motor's internal voltage regulator circuit board... http://i240.photobucket.com/albums/f...3/SCORCHED.jpg The motor's voltage regulator had burned itself up. Look at how scorched the circuit board is! I have a replacement regulator, but I want to make sure that all is well inside this circuit before installing the replacement. (Yes, I KNOW that I could simply get another motor, but remember, I am tinkering for the sake of tinkering!) So I have been checking all of the other components in this circuit, to verify their health. The one component that has me puzzled is the small black "diode" indicated at the bottom of the photo. There is no mark on this component other than the yellow stripe you see. I cannot get any type of reading on this component when I use my multimeter -- I get nothing using my diode check function (forward or reverse bias), no continuity, no resistance reading. It must be faulty, I am assuming. Then you're somewhat stuffed without a schematic I'm afraid. Unless you can reverse engineer the circuit ! I've just been through a similar problem myself where the parts list had everything on it except RESISTOR values ! what IDIOT was responsible for that I hate to think. For any AUDIO people listening, that company was MIDAS btw. I've been in contact with them for about 2 weeks now about it and all they did was to re-send the same list in a different file size with the resistor values STILL missing. The other component that has me puzzled is the olive green "resistor" just above the larger blue electrolytic capacitor. I get a steady resistance reading of .5 ohms on this component. Plausible. Low value Rs aren't always marked conventionally. Most likely a current sense R. Graham |
#28
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HELP - Please Identify These Two Parts....................
N_Cook wrote: Is the diode oriented to soak up back emfs from the motor ? The green thing is an inductor Both very plausible. Graham |
#29
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HELP - Please Identify These Two Parts....................
Jamie wrote: that diode is suppose to go across the motor leads to suppress back EMF which can damage components.. It would be a simply low current SI diode. In which case putting in something bigger like a 1N400x ot UF400x if it has to be a fast device would do no harm. I've known 'back emf diodes' like the 1N4148 to be 'killed' by even modest size relays. I never 'cut corners' on that component any more. 1N400x every time. Graham |
#30
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HELP - Please Identify These Two Parts....................
EADGBE wrote: The anode of the diode is attached directly to three of the resistors as shown. I have tried to re-create the circuit board traces on the other side. The cathode connects to what N_Cook has described as an inductor. Take a look at this photo: http://i240.photobucket.com/albums/f...e123/DIODE.jpg Thanks to everyone for your help so far. Can you not trace out the whole circuit ? There's precious little there. Graham |
#31
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HELP - Please Identify These Two Parts....................
EADGBE wrote: Actually, I'll do just a bit better. Here are ALL of the circuit board traces, done as best as I can. Let me know if the traces aren't clear enough: http://i240.photobucket.com/albums/f...23/CIRCUIT.jpg By the way, the AN6601 laid flat against the circuit board, with the label side DOWN. Oh, go on, draw a schematic ! BTW, that black electrolytic may well have had a good cooking. I'd replace that too. Graham |
#32
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HELP - Please Identify These Two Parts....................
Well, it has all become academic at this point.
I ran the motor off of a 9v battery while it was hooked up to my multimeter's current setting. The motor was pulling just over ONE AMP of current! I took apart the casing and studied everything....sure enough, one of the armature windings has a scorched spot. This motor has gone to that Great Cassette Deck in the Sky.... |
#33
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HELP - Please Identify These Two Parts....................
"EADGBE" wrote...
Well, it has all become academic at this point. I ran the motor off of a 9v battery while it was hooked up to my multimeter's current setting. The motor was pulling just over ONE AMP of current! I took apart the casing and studied everything....sure enough, one of the armature windings has a scorched spot. This motor has gone to that Great Cassette Deck in the Sky.... You could have re-wound the motor! :-) |
#34
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HELP - Please Identify These Two Parts....................
On Oct 7, 2:14*pm, "Richard Crowley" wrote:
You could have re-wound the motor! *:-) Yeah, I know...but I'm just too lazy! :-) |
#35
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HELP - Please Identify These Two Parts....................
"EADGBE" wrote in message ... On Oct 7, 2:14 pm, "Richard Crowley" wrote: You could have re-wound the motor! :-) Yeah, I know...but I'm just too lazy! :-) There are replacement motors available from MCM and the like... 12V CCW, 12VCW, etc. Standard mounting holes. Usually pretty easy to wire in place of the original. Mark Z. |
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