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Electronics => Projects, Designs, and Technical Stuff => Topic started by: luky315 on September 17, 2012, 07:34:39 am

Title: Inductive / Capacitive Dummy load
Post by: luky315 on September 17, 2012, 07:34:39 am

Has anyone a good Idea how to build a Dummy load with 0..0.1F and one with 0..0.01H? I found only resistive Dummy loads but a variable inductive / capacitive load is really useful for stability tests. The load current should be >2A. Any Ideas?

Title: Re: Inductive / Capacitive Dummy load
Post by: Rudolfo on September 17, 2012, 08:05:42 am

Ultracaps maybe a solution. There are some with 1.5F but 5V only.

Enjoy your design work!

Title: Re: Inductive / Capacitive Dummy load
Post by: luky315 on September 17, 2012, 08:49:33 am

I need an adjustable load.

Title: Re: Inductive / Capacitive Dummy load
Post by: Rerouter on September 17, 2012, 08:55:53 am

here you go http://tinyurl.com/9qfhh4d (http://tinyurl.com/9qfhh4d)

that is for variable capacitance, you will have to size the pot and cap accordingly for your range,
and to get variable inductance, you only need to flip the connections of the pot and cap so that the pot is to ground and the cap is to the voltage rail

hope that helps :D

Title: Re: Inductive / Capacitive Dummy load
Post by: luky315 on September 17, 2012, 02:30:21 pm

Thx, i will try it out!

Title: Re: Inductive / Capacitive Dummy load
Post by: ejeffrey on September 17, 2012, 02:41:36 pm

What frequency and voltage?  Do you care about the DC behavior?  Does it have to be a true (energy storing) reactance or can you use feedback like a gyrator circuit?

Anyway, the simplest solution would be a variac.  Just use the output alone (protect the input plug so nobody get shocked) as a variable inductor.  For a variable capacitor, connect a large fixed capacitor and use it as an impedance transformer.  You will have to look closely at the current and voltage ratings to make sure you don't overload something.