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capacitor bank

You could build a suitable capacitor bank with about $20 worth of these electrolytics. 470uF 450V Radial Electrolytic Capacitors PCB DIP Component 1pcs 20 150 If you think you need more than 23 uf to remove any detectable ripple, you're fooling yourself. The one significant advantage oil filled caps have over electrolytics is their ability to handle higher current. I promise you won't get any hum with just 20 of those caps but if you want the current advantage too, buy 40 of them and put two banks in parallel for twice the current and 47 uf of filtering. All for $40 delivered!

Here are 50 caps for $50 and a US seller: http://rover.ebay.com/rover/1/711-5...0001&campid=5336136228&icep_item=290442460635
 
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over doing it on the uf arent we? 15-40 uf on a 3000 WOW

Not really. The higher the current draw the more capacitance you want. If you have a choke input supply then you can get away with 10-15 uF easily but for a simple capacitor input supply 50 uF on a 3000 volt supply running two amps is marginal for best ripple rejection and dynamic regulation. Supplies like that usually require step-start to prevent blowing the rectifiers or welding the power switch.
 
on my 3000 I have under 5 uf of cap. 3 caps in series for 12,000 volt.
It's a mobile. 2 alternators, I dont rev up or down. Key it like a dc box and no rectifiers blown.
to much cap can be counter productive

Oh abosolutly zero noise from anything. box, power supply or in my tx.
 
on my 3000 I have under 5 uf of cap. 3 caps in series for 12,000 volt.
It's a mobile. 2 alternators, I dont rev up or down. Key it like a dc box and no rectifiers blown.
to much cap can be counter productive

Oh abosolutly zero noise from anything. box, power supply or in my tx.

Mobile, you are running 3 phase. You could use 1uF and get away with it. 5uf is about max for mobile.


You won't like this but .....there is making a CB amp work and then there is making an amp the proper way. Good engineering principles says otherwise. 5uF without a choke in the power supply is not the proper way when we are talking 60 Hz filtering. Then again 800 watts from a 4 pill class C box on AM is not the proper way to do it either but that has never stopped people before. :pop: Running that mobile I have no idea what the AC frequency to be rectified is as it would depend on the alternators used as well as the engine speed. Higher frequency AC is easier to filter with lower values of C.
 
In mobile, 1uf will get you by. 7uf is about max. Guy use alternator and hook up winding in alternator. Working with better than 400hz. After 7uf. Cannot discharge quick enough. That is why you are suppose to idle engine down before you unkey. Sotube actually bleeds down some of the power. If using boost on amp. Can see upwards of 10kv plus on the plate. That's when things really start to arc.
 
And watch the power meter spin...


No thanks. I had the service guy here yesterday. The heatpump was not going into aux. heat mode. Turned out to be a bad thermostat. When the aux heat was turned on manually the 15 Kw of electric backup made the meter look like a frisbee spinning. :eek: I can't imagine more than that. Besides I don't have three phase power in my house so I can't be tempted. :D
 
Even for a base these cap numbers are large. 40 uf for a 3000. thats enough cap for a pair of 15,000 How big of a resistor are you putting on the soft start?
 
I like about 30-40uf. But you have to soft start both legs and put a 3-5 second delay. Better use at least 200W resistors @ 50 -100ohms. Did this with a couple of 3000's and lights didn't flicker and no grunt from transformer during power up. Kinda cool really. Watch it jump from 0-2kv and just slowly climb up to 6kv.
 

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