Q&A Forum
So i wonder if i can use/make some sort of filter to make the circuit work, or if it isnt needed at all and the transformer
can handle it?
Or should i just keep looking for a retarder that can be run on 192v and skip the transformer?
Regards Jesper
I'm solving exactly the same task with my water cooled eddy current engine dyno (96V, 2A). I decided to build my own driver with constant current output, so no PWM. I don't know, if you are in a hurry, or you can just wait for my solution...
Hi,
Lots of dynos run on 96V. The SportDevices brake supply supports it without a problem. You can also use other supplies, just know the current is a spiky with the switches (thyristors or similar) on maximum 50% of the time. So at max power, the current is twice the rated current for 50% of the time, so choose components to support this. A 220V-110V transformer lowers the max current, but the average current is the same.
"110V transformer lowers the max current" ... Are you sure? Why would it do that? It lowers the voltage to 1/2 and potentially doubles the current, if it's made as beefy as it should be.
Hi, yes the average current is set by the brake and the voltage, it is the same in any configuration. But if you use 220V AC to create 0-96V DC, then the switches that draw current from the AC will never be on more than about half the time. So in that time the current will be roughly double.
It looks like we are both talking about different things. I was talking about normal transformer and you are talking about switch mode power supply, right?
Also the brake can be considered an ohmic load, if you drive it in a constant current mode. In that case it's also true, that with decreasing voltage the current decreases as well.
It looks like we are both talking about different things. I was talking about normal transformer and you are talking about switch mode power supply, right?
Also the brake can be considered an ohmic load, if you drive it in a constant current mode. In that case it's also true, that with decreasing voltage the current decreases as well.
Please explain ? Or is it a secret, or can you divulge more information ?
There's no secret. I just don't want to feed the brake with PWM signal.
There's no secret. I just don't want to feed the brake with PWM signal.
That part I understood already! "if you drive it in a constant current mode. "
Going to be physically one big transformer!