Power Supply 24 V ,50 V and 70 V This homebrew power suply first was 24 V and 50 V, now it is adapted and an 70 Volts trafo is adapted. First a few pictures of the old power supply.

Front

From above

Down under.

On the next pictures you see the changes of the Power Sulpply, a 70 volt Trafo is added for the
new PA.

(17-6-2007)
Inside you see the 24 Volt Trafo and the wiring from the other trafo's. 

(17-6-2007)
On the top you see the 70 volt trafo and the 50 volt trafo on the rear side. 

(17-6-2007)
The 50 volt trafo is placed on the rear, because there is no place inside HI. 

(17-6-2007)
The front is also changed to measure the currents of the 50 V and 70 V trafo's

Only need to add a switch with relay, so I can switch the 50 V trafo on and off.

(10-8-2007)
Ai Big problems, I told it before the Power supply was to small. Here you can see what happends.
I was busy to make a BPSK31 QSO with a OH station and a big cloud of smoke came out of the 
Power supply.. You can see a black spot on the elco, I think a flare passed there. 

The temperature must be very high. I forgot to cool the power supply.

Blisters on the trafo.

(11-8-2007)
But if there is a problem, there is also a solution. I had a QSO in the QRP-Net, and OM PA0YG
invited me to come to his house to look for a Trafo. And indeed he has one HI... 70 A by 43 V.
See the difference. I think the temperature problems are over now !!.

OM PA0YG also tolded me how to deal with the peak current when i switch this Power Supply on.

(16-8-2007)
I have made a start to put this power supply together. I have used a heating element instead of 
a big resistor.

(23-8-2007)
I placed the components on a board, for testing the power supply.

The elco's i used are the following, 5 x 22.000 mF 100 Volt

When i switched the power supply on there was no dip and it starts up smoothly, so the schematic
spoken above works perfectly !!.

After testing and take some measurements I
 start to make the casing and wire the Power Supply.

I am replacing the test wires for aluminium strips.

Wiring compleet with the shunt resistor for the current panel meter.

The lid placed on the powersupply (with holes) , so the heat can leave the building !

The power supply in place, and it works well.

The bare Power supply is ready and gives 60V by 50 Amp., but i am going to expand this 
power supply in the same casing with some extra electronica so i can regulate the voltage and the

current ( lab power supply ).

Come back to see the results ....

73