Amplifier issue velleman

Thread Starter

CosmicOrderMachines

Joined Oct 31, 2019
76
Can somebody help me? I'm trying to put a load into a primary winding of a small tesla coil. Some reason this amp wont do it. I have a tiny 5 watt amplifier consuming literally 0.7 watts @ 78khz (the resonate point of the coil where I can measure the surrounding voltage spike with an oscilloscope). I have a small resistor in series with the primary on this little amplifier set up and control with a bench supply nice and easy so I don't fry the amp. So I have this velleman, which sucks at high frequency, but can still put out more power at 78khz then that small amp. However no response in the coil. All that trickles through is 60hz power. I've tried to put a 25watt 4ohm resistor in series thinking that may simulate a load, the amp claims to have overload and short-circuit protection. I thought that might work, but nothing. How do I disable the overload/short-circuit protection. Or how do I simulate this load. Sorry I am so noob at electronics. I am learning

Velleman source.png
 

AlbertHall

Joined Jun 4, 2014
11,302
To disable the overload protection remove D1 and D2. You could also rmove T4, T5, R5, R6, R16, and R17 as they would them have no function.
But note that then an overload might fry T7 and T8.
 

Thread Starter

CosmicOrderMachines

Joined Oct 31, 2019
76
The amp behaves 100 times better now. Way more linear power through the high frequencies. The voltage used to drop like a rock at 12khz-50khz no load. It doesn't even budge anymore. Stays same voltage to even higher frequencies. The over current protection absolutely killed this amps potential. How? If you don't mind answering. Or rather I think I'll find out myself, but you can just know this changed the linear response by an insane amount.
 
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