Re: SCR based coils (was High-Power Car Ignition Coils)

To: tesla-at-pupman-dot-com
Subject: Re: SCR based coils (was High-Power Car Ignition Coils)
From: "danial stocks" <diode-at-hotmail-dot-com> (by way of Terry Fritz <twf-at-verinet-dot-com>)
Date: Sun, 17 Jan 1999 15:20:34 -0700
Approved: twf-at-verinet-dot-com


>At 05:10 PM 1/15/99 -0700, you wrote:
>>Original Poster: "Bill the arcstarter" <arcstarter-at-hotmail-dot-com> 
>>Any clue what the max reverse gate to cathode voltage should be?  It 
>>isn't spec'd in any of my books - and I exceeded it bigtime last night 
- 
>>killed one of my scrs in the process... :(
>>
>>-Bill

>
>From looking at my Powerex data books it looks like max peak reverse 
voltage
>for the gate to cathode is in the range of 5-10 volts. I hope you have 
some

>Eddie Burwell
>
There is an equivalent circuit description of SCR as a pnp & npn 
trnsistor connected - ie scr (a) = pnp (e), scr (k) = npn(e), 
npn ( c)& pnp (b) conn internally, npn (b) & pnp (c) = gate
if you consider it like this then scr g-k junct is npn b-e junct
Most transistors even really big ones have Veb ( rev base vtg) ratings 
of 3-8 volts... Reverse pol diodes across g-k would be a universally 
good idea I feel .

Danial Stocks


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