17th Sep 2015, 5:09 pm | #101 | |
Tetrode
Join Date: Mar 2015
Location: Ashford, Kent, UK.
Posts: 93
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Re: Solid State Vibrator.
Quote:
Finally, they mention "soft start". It is possible for the transformer magnetic circuit to have significant remanence and if you start the converter up with a 50/50 duty cycle straight away it's possible for it to saturate and draw BIG currents. Mallory vibrators were designed to start from a low duty cycle to avoid this. So, I'll use a nice cheap 3525 with inbuilt soft-start and duty-cycle limiting to drive a pair of MOSFETs. Simple. Graham |
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22nd Sep 2015, 8:39 pm | #102 |
Tetrode
Join Date: Mar 2015
Location: Ashford, Kent, UK.
Posts: 93
|
Re: Solid State Vibrator.
More -
I've made it and it fits inside the original can on a piece of Veroboard. It's designed for a positive earth system so uses P-channel MOSFETs. Good h.t. in the radio (220V), fairly quite and runs very cool. Only problem now is to get the front end working properly. Graham |