On the next pictures you see the changes of the Power Sulpply, a 70 volt Trafo is added for the
Inside you see the 24 Volt Trafo and the wiring from the other trafo's.
On the top you see the 70 volt trafo and the 50 volt trafo on the rear side.
The 50 volt trafo is placed on the rear, because there is no place inside HI.
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.
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.
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.
I have made a start to put this power supply together. I have used a heating element instead of
a big resistor.
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 ....