WOPL 400 Build Problem!

[laatsch55]

Well, we don't want any outputs in yet. After you remove the outputs, bring it up on the DBT to check for shorts in the power supply.

 

[nadude98]

Well, we don't want any outputs in yet. After you remove the outputs, bring it up on the DBT to check for shorts in the power supply.

Well, I had already, brought it up after retesting for shorts with the bottom row of outputs in as per the instructions for bringing it up for the first time. I removed the ground wire and tested from output cases to chassis ground and had infinite resistance. I reconnected the ground wire and put the 10k resistors between output tp and ground tp and brought it up on the DBT and checked the B+ and B- for appropriate voltages. B+ was +84.5 and B- was -84.5, I then installed the rest of the outputs and posted. If you want me to pull them I will, and if so how do you want me to test for shorts in the power supply?

 

[laatsch55]

You've already done that. Reinstall the board. Check offset as you bring it up. If you have excessive offset after 60 volts on the rails shut down and remove 6 and 9 wires and try again.

 

[nadude98]

You've already done that. Reinstall the board. Check offset as you bring it up. If you have excessive offset after 60 volts on the rails shut down and remove 6 and 9 wires and try again.

Had to order a variac... be here later this week, I hope.

 

[laatsch55]

I forgot you did not have one. Not really necessary here, but now that you have it ordered it would be nice to use it...

 

[laatsch55]

When you checked the power supply did you check the +/- 15 volt supply?

 

[nadude98]

When you checked the power supply did you check the +/- 15 volt supply?

I haven't put the driver board on yet, if that is what your referring to... if your talking about the feed to the meter lamps, they are working but I've never checked the voltage.

 

[nadude98]

When you checked the power supply did you check the +/- 15 volt supply?

Would you diagram testing the TL431 by pin please? I believe I did it correctly but I would like to make sure

 

[Gepetto]

Would you diagram testing the TL431 by pin please? I believe I did it correctly but I would like to make sure

It is an IC, not a transistor. It either regulates at 15 V or it doesn't

 

[NavLinear]

Here's the data sheet for the voltage regulator.

 

[nadude98]

It is an IC, not a transistor. It either regulates at 15 V or it doesn't

laatsch55 told me to test it and that it should test like an NPN transitor.

 

[Gepetto]

laatsch55 told me to test it and that it should test like an NPN transitor.

No it is a integrated circuit which functions as a precision zener reference when in the circuit. It does not test like an NPN transistor.

 

[nadude98]

When you checked the power supply did you check the +/- 15 volt supply?

Something seems strange to me. After I took everything apart and restarted using the DBT it doesn't even light up at all anymore.....? Used to get real bright and then dim out...Not sure what's up with that!

 

[Gepetto]

Something seems strange to me. After I took everything apart and restarted using the DBT it doesn't even light up at all anymore.....? Used to get real bright and then dim out...Not sure what's up with that!

It probably means that your bulk caps are still fully charged. Be careful. Discharge them with a 200-1K resistor.

 

[nadude98]

It probably means that your bulk caps are still fully charged. Be careful. Discharge them with a 200-1K resistor.

Dang, I would have thought they would have discharged overnight.. I have a couple of 1k's with clips I've been using.. Thanks!

In the USAF we used to use shorting rods on the big caps.... that was always interesting!

 

[laatsch55]

No it is a integrated circuit which functions as a precision zener reference when in the circuit. It does not test like an NPN transistor.

.. .I could have swore I b saw two junctions on em Joe...

 

[Gepetto]

Dang, I would have thought they would have discharged overnight.. I have a couple of 1k's with clips I've been using.. Thanks!

In the USAF we used to use shorting rods on the big caps.... that was always interesting!

A good way to do welding

 

[nadude98]

No it is a integrated circuit which functions as a precision zener reference when in the circuit. It does not test like an NPN transistor.

Ok, well I had an order to get from mouser to recap a Pioneer A60, I added a couple of those to the order and it'll be here tomorrow. Maybe I should replace since there was an issue with +15v side

 

[Gepetto]

.. .I could have swore I b saw two junctions on em Joe...

If you did Lee, it is purely accidental...

 

[laatsch55]

Wouldn't be the first time Sir Joe...