JSR03 - information

[peranders]

R13 may be decreased, down to 2k2 is OK but at least so you'll see some light from the LED.

I'm off now, see you next week.

[Keljian]

R13 may be decreased, down to 2k2 is OK but at least so you'll see some light from the LED.

I'm off now, see you next week.

ok see you

[Keljian]

I think you were right P-A..

I'll get a much more powerful transformer (160VA ) in the coming week...

[Keljian]

well after changing the transformer, it works a charm...

thanks for all your help PA.. oh .. I did some testing and you really need to feed it about 8-9v more than you want out of it.

[Keljian]

well after changing the transformer, it works a charm...

thanks for all your help PA.. oh .. I did some testing and you really need to feed it about 8-9v more than you want out of it.

famous last words..

it's not working so well anymore, must have tapped it by mistake or something, Voltage across R9 is 2.3v, voltage across DZ1 is 6.7v, Vout is 8.5v

I've changed the regulator for a new one, and changed T5, not that it's made any difference.. I'm guessing there's a problem with the feedback loop but I don't know what the problem is.

voltages across transistors = 0.7v

resistors seem in spec

Followed the schematic, the problem is the reference, was outputting 22v

[peranders]

Did you have enough cooling?

How are you getting 22 volts from the reference if you feed it from 8.5 volts?

What did you do to get the regulator broken? Remember that it has limited short circuit protection. It's not totally fool proof.

[Keljian]

welcome back

I've always fed the regulator with the same 33.5v or so

I killed it by shorting the back of the regulator (the lm317) to output ground. it is outputting 8.54v, r9 is 2.30 v or so.. I intend to change the LM329 today as the voltage across it relative to ground is 22v or so

using a thermal probe I measured the temperature when it was running properly the d44h11 was running at 70C and the LM317(with heatsink) was running at 60C (ambient approx 25C )

[Keljian]

welcome back

I've always fed the regulator with the same 33.5v or so

I killed it by shorting the back of the regulator (the lm317) to output ground. it is outputting 8.54v, r9 is 2.30 v or so.. I intend to change the LM329 today as the voltage across it relative to ground is 22v or so

using a thermal probe I measured the temperature when it was running properly the d44h11 was running at 70C and the LM317(with heatsink) was running at 60C (ambient approx 25C )

well it's not LM329.. I just changed it.
the voltage is still 8.54 coming out of the JSR

I'll trace the circuit again tonight..

[peranders]

As a permanent solution I think 70 deg C is a bit too much. Notice that the lifetime of the electrolythic caps will be shortened.

[Keljian]

As a permanent solution I think 70 deg C is a bit too much. Notice that the lifetime of the electrolythic caps will be shortened.

I'll be putting a bigger heatsink on it when I get some thermal compound, once it's functional. I have one sitting here, in the meantime I need to get it working again, and I have no idea where to start.

[Keljian]

9.74v across the lm317

6.91v across the diode

2.317v across r9

1.310v across r7

1.227v across r1
1.282v across R2

[Keljian]

well I replaced the d44h11, 29.7v out.. output definately isn't stable


8.15v-8.55v across R9

6.75v across DZ1

0.75v across the led

7.15v going out of the LM329 (shouldn't this be 6.9?)


getting closer..
LED is off

[Keljian]

replaced transistors(t2, t5) , replaced diode.. output voltage back to 8.5

I'm on the verge of giving up with this supply

readings as in previous post

9.74v across the lm317

6.91v across the diode

2.317v across r9

1.310v across r7

1.227v across r1
1.282v across R2

[peranders]

I'm on the verge of giving up with this supply

This design is pretty easy to get working I have built a number of them and tehy all worked right away.

The only thing you have to do is work carefully and don't rush.

All things you have done so far are the result of that you have been eager to get it ready.

You see have my reference design looks like, plan the changes, write them down, do some calculations if necessary and if you want some help just ask.

I'll be back in a week.

[Keljian]

I'm on the verge of giving up with this supply

This design is pretty easy to get working I have built a number of them and tehy all worked right away.

The only thing you have to do is work carefully and don't rush.

All things you have done so far are the result of that you have been eager to get it ready.

You see have my reference design looks like, plan the changes, write them down, do some calculations if necessary and if you want some help just ask.

I'll be back in a week.

Perhaps, but I've had enough of the design, and the board is on the verge of being unusuable after having so many things soldered/desoldered from it. I've moved to a simpler design(on protoboard) for now, I may revisit it later, but for the momen I'm using what works