oldbee
Well-Known Member
"Way past my pay grade"(!) but a very interesting thread. I've done seemingly everything up to 220v and can't quite wrap my head around what it's trying to do. Jeez, now I'm getting mad that I can't figure it out.
Old Craftsman 2/10/50 charger/starter not functioning properly
- Thread starter 68gtxman
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Is this your charger being discussed, or someone else with exactly the same scenario? http://www.antiqueradios.com/forums/viewtopic.php?f=2&p=2688124
As I slept last night, I figured that the glass tube is a thermal switch, so it is probably not the problem. It seems that the root problem is probably the diodes that are mounted on the heat sink board. I guess that they can be tested by checking continuity thru each one and see if they will read continuous one way and not the other. If they read continuous both ways, they must have failed - right? I'll make this test a little later today.
FYI, the charger is from the early 1980's. Thanks for your continued help and advice!
FYI, the charger is from the early 1980's. Thanks for your continued help and advice!
All 4 diodes tested open one way and 88.6 ohms the other way. Is this normal? (I would think it probably is.)
One of the diodes looked like it was partly separated from the heat sink, but it tested the same as the others.
What should I test next?
One of the diodes looked like it was partly separated from the heat sink, but it tested the same as the others.
What should I test next?
Why didn't I do this before??? I just tested the power output at the battery cable end. It was not registering on the D.C. scale so I switched it over to AC. When set to 12V, it read 26.8 volts. It didn't change no mater what switches or dials were changed except for the switch to output 6V, and then the voltage dropped to 13.6 volts.
Even when the switches were set to OFF, it still output the voltage shown above.
This has got to be a pretty simple problem to fix unless I am way wrong.
Even when the switches were set to OFF, it still output the voltage shown above.
This has got to be a pretty simple problem to fix unless I am way wrong.
Really? Sylvania stopped using that logo in the late 1960s; I guess the manufacturer had lots of what ever that thing is on the shelf.
One of the old timer engineers here at work suggested that the glass tube could be a voltage regulator. These were filled with gas (for example neon), and the gas ionized (glowed) to regulate voltage. Not saying that is what this is, just sharing a few comments.
Still thinking about this.............
Still thinking about this.............
I do not see any large 'filter' capacitors in your pictures. If this is a half wave rectifier, then the AC you are measuring might be okay. The battery connected becomes the 'filter'. I do agree it is strange that the off position has any voltage present.
Have you spray soaked all contacts with DeOxIt? It is just a simple thing to do just to add some confidence the switches are doing what the design intended.
The contacts inside the timer switch (the only one I opened so far) looked pristine. I don't have any Deoxit, but I will get some.
Can you tell me the proper way to test diodes for proper operation?
Infinity one way, but 88.6 ohms the other way. Shouldn't it be 0 ohms?
OK, so now I am officially stumped on this. The control panel is no longer available as a replacement part, so I need to diagnose the failed component(s) and find a fix for it. Any further diagnostic thoughts?
This is not exactly what I was looking for, but it might help you:
http://www.universalrectifiers.com/PDF Files/Troubleshooting.pdf
Try googling 'troubleshooting half wave rectifier circuits' and see what material you get.
An ohm meter will help you determine if the transformer (primary and secondary) windings are open.
A voltmeter will help you confirm if proper voltages are present; AC should be across the rectifier's input, and DC on the output.
I'll see if I have any basic universal charger schematics I can scan and reference for you.
http://www.universalrectifiers.com/PDF Files/Troubleshooting.pdf
Try googling 'troubleshooting half wave rectifier circuits' and see what material you get.
An ohm meter will help you determine if the transformer (primary and secondary) windings are open.
A voltmeter will help you confirm if proper voltages are present; AC should be across the rectifier's input, and DC on the output.
I'll see if I have any basic universal charger schematics I can scan and reference for you.
Sonny Black
Well-Known Member
$20 bucks
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