In article , "John Giddy" wrote:
Hi Peter,
Good circuit !
However I have a couple of questions:
1.
I presume the FET (Q2) will need a heatsink, as it will
dissipate approximately 12W when discharging at 1 Amp ?
2.
R9 should be 470 ohm, not 470 K

Cheers, John G.

John you are right.

The FET needs a heatsink, as it works as a variable power resistor to provide
a constant discharge current
And R9 should have 470 ohm to turn on the monitor LED.

Thanks
Peter

Peter Nyffeler
Tel P 01 363 62 42, Tel G 01 632 43 60, Fax G 01 632 10 21