Beginner Has Some Questions...aleph

HI GUYS,
I'M STEVE, AND HAVE BEEN FOLLOWING ALONG FOR AWHILE, BUT BEING A BEGINNER I DON'T HAVE MUCH TO ADD. I'M STARTING TO BUILD AN ALEPH 1.2 AND HAD SOME QUESTIONS.
L RESISTORS; THE "BRAND" I WOULD LIKE TO USE DOESN'T OFFER THE EXACT VALUE EXAMPLE:
221 THEY OFFER A 220
392 THEY OFFER A 390
IS THIS A PROBLEM?

2. CAPACITORS: I'M CORRECT IN ASSUMING THE VOLTAGE RATING ON THE POWER SUPPLY CAPS. SHOULD BE GREATER THAN 60V? 25000UF >60V? ALSO DOES THIS HOLD TRUE WITH C-5, C-6, C-7 ETC.

3. WAYNE WHERE DID YOU GET THAT NICE ROCKER SWITCH FOR S-1. RATED FOR 25A? DOES IT NEED TO BE?
THANKS, STEVE
 
Power Switch Rating

I'm not familiar with Aleph 1.2 .... but let me assume that 20A circuit breaker is sufficient for this amp ....... typically 15A is the maximum current allowed for No.12 conductors (Al or Cu-clad Al) .... from the house electrical panel to the receptacle ..... after any correction factors for ambient temperature and number of conductors have been applied.
 
Hi Steve,

I am working on my Aleph 0 project, and I found this resistor-problem too... Perhaps the US uses a different system in Resistor grading? I noticed that in ALL Projects the resistor values are off about 1 ohm to what I'm used to.

All I know is the E220 resistor system, which steps through all values like this: 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82, 100.

Is this different than a supposed US system?

You could just as well add a 1 ohm resistor in series with 220 to get 221, but that's not what I prefer...

Bouke
 

WayneS

Member
2002-03-24 11:44 pm
Dallas
Hmmmmm... don't know if I'm the wayne you want but here goes anyhow...

The switch in my amps are from Digikey, it's their part number 360-1488-ND.
As someone previously said you can wire the 2 poles in parallel to
hopefully help out a bit with the turn-on current surge - I didn't do this to mine. I hope they don't die an early death but they seem to have no trouble so far.
 
We're talking transformer ...not motors ...... so, I don't see why we need to use more than 15A switch. Example: Full load current for a 1000VA transformer is less than 10A. If we allow 75% more for in-rush current , 15A is still o.k. If it goes a lot higher than that, the circuit breaker at the electrical panel would trip before it even have a chance to destroy the switch.
 

WayneS

Member
2002-03-24 11:44 pm
Dallas
Yes, there are the two factors listed above that produce huge inrush currents. I think Nelson talks about 50A and higher turn-on surges. My caps are short circuit - 88,000 uF worth. THe only
saving grace is the thermistor in the primary circuit which is about 9 ohms at turn-on. You need a big switch, the only question is whether my switch is big enough... time will tell.

BTW, the lights in my amp circuit go quite dark for a short time when I turn on the amps - the surge is quite pronounced.
 
Hello,



The enclosed circuit can help you with some problems that you haveing.
Also with that, you can use whatever switch you want, without any problems.



Kristijan Kljucaric
 

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