OK, tried that, still no joy 🙁
Next question. In the schematic in post 715, is the TAB of the IXYS shown by the solid line to the left of the 3 borken lines?
Next question. In the schematic in post 715, is the TAB of the IXYS shown by the solid line to the left of the 3 borken lines?
Hope this helps , the metal part in the back of the Transistor is connected to the Drain pin .
Attachments
yes - and you must have insulator between metal part of transistor and heatsink
as insulator use ready made mica or silicone pads
as insulator use ready made mica or silicone pads
Yes, that's what I thought. Thanks for the confirmation. So, I appear to have it wired correctly.
I am getting 82v to the bulb, but it doesn't light and the safety bulb mains lead glows brightly when I insert the bulb, suggesting a fault. Everything is ok until I fit the bulb. Bulbs are 300W - 130v.
Are these any good?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The big 1 ohm resistor that stands for R4 ( 50 watt I guess ) is it connected to the chassis ground ?
The metal cased 1 ohm resistor is not wired up at present the PS is a CRC with some wirewound resistors. I was going to use these if the others got too hot.
that is probably too small in power to be working well , or at all . Check it , it may be broken
OK. Thanks for all your help. I'm off to bed now. Will tinker with it again and report back
Regards
Rob.
Regards
Rob.
P=I^2 x R
if current is , say , 2A then - dissipation P= 2^2 x 1 = 4W
that calls for at least 10W resistor ; preferably heatsinked
if current is , say , 2A then - dissipation P= 2^2 x 1 = 4W
that calls for at least 10W resistor ; preferably heatsinked
I think there may be some confusion on the Gate & Source. What looks like an internal connection between the gate and source in the MOSFET graphic is NOT an external connection. The source pin should ONLY be connected to R4.
Roscoe
Roscoe