If you switch EF output stage in open loop it will remain stable, same is the case with unity gain CFP, i have tried both approaches, but the moment you put some GAIN in output as in CFP the stability is compromised. Like in QSC PLX series they are limiting the slew of step switch to preserve stability because the output is having gain. In old QSC such as MX and RMX series the output stage is grounded collector type and is having unity gain, so there is again no problem in stability.
If you compare old MXa series with newer PLX series the old ones are more reliable, i have seen amplifiers working from past 15 year without a single fault but same is not case with newer generation amps of QSC. MXa series is that amplifier who has made qsc's reputation in reliability.
IR2117 circuit is more reliable as it operates the mosfets with minimum losses due to faster speed. It has been used in many amplifiers which are even 3 to 4 steps class-H.
There are many alternative gate driver chips on market if IR2117 is not available. One can try these:-
FAN7361
&
FAN7371 for high current bigger mosfets.
hi engel, i get fast recovery rectifiers from discarded pc monitors, you will be surprised how many parts you can take out from those....http://www.datasheetcatalog.com/datasheets_pdf/B/A/V/2/BAV21.shtml
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sir tony,
i manage to get back to back diode instead of sfa1603
also from pc psu
this bf 421 or mpsa92
nsl32 or any opto
and this bav21
this is my head ache
sir can i use two 1w 15v zener if i did'nt manage to get 2w?
engel, to be able to come up with substitutes, you must understand how a particular component functions in a given circuit....what current and voltage will it see? how fast is the signal going to be? analysis of the circuit allows you to see this.....
afaik, zeners are 1/2w, 1, and 5watts, if you know how much power a zener will dissipate in a circuit, then you can decide for your self.....
