EEVblog Electronics Community Forum

Electronics => Projects, Designs, and Technical Stuff => Topic started by: kc9qvl on April 08, 2014, 01:59:50 am

Title: 120 watt / 30 watt constant current load.
Post by: kc9qvl on April 08, 2014, 01:59:50 am

I originally asked for information in the beginner forum. After a couple false starts making some real headway.  Decided to build a dual input one high wattage and another low wattage. Panel meters will only do amps. Not going to worry about volt measurement I'll just use a multimeter.

Built a custom aluminum resistor block from ceramic resistors. One section  0.25 ohm can handle 150 watts at  C. Tested this connected the 4 1 ohm resistors in series  Ran 25 volts 6 amps into the resistor for 2 days didn't fail. No looks good no cracking in the fire cement. The 1 ohm section 50 watts input didn't even heat up. The 2 fets are bolted right to the heat pipe. So the heatpipe itself is insulated. More to follow.

Title: Re: 120 watt / 30 watt constant current load.
Post by: mjkuwp on April 08, 2014, 02:48:37 am

cool!  What is it for?

Title: Re: 120 watt / 30 watt constant current load.
Post by: kc9qvl on April 08, 2014, 02:57:03 am

Constant current dc load.

https://www.youtube.com/watch?v=8xX2SVcItOA (https://www.youtube.com/watch?v=8xX2SVcItOA)

Title: Re: 120 watt / 30 watt constant current load.
Post by: Towger on April 09, 2014, 08:54:17 pm

Low tech version: https://www.youtube.com/watch?v=WECW88rJYrE (https://www.youtube.com/watch?v=WECW88rJYrE)