On 12-31-97 Robert Sayre wrote to Day Brown... 
 
 RS> DB> Well this thread is getting kinda strung out, but have any of 
 RS> DB> you guys considered using something other than a diode on PV 
 RS> DB> panels? 
 RS>  
 RS> DB>  seems like I could use a 20 amp relay powered by a paralel tap 
 RS> DB> on the panel that would only draw (thru a 200 ohm coil) 60ma 
 RS> DB> or less than one watt, and diddly for heat. 
 RS>  
 RS> DB>  Or maybe one of these new IGBT gizmos, that says it has .05 
 RS> DB> volt across it, and diddly for the drive on the gate. 
 RS>  
 RS>  Why not use a MOSFET ? 
I thought the IGBT had less power loss.  The gate drive is so low that 
a separate Si solar chip could power it? 
 RS>  
 RS>  How are you going to determine the time to switch ON or OFF? 
 RS> Normally, that would be done by sensing a voltage drop. 
no light on the Si detector. 
 RS>  
 RS>  This is why I suggested a Schottky diode. IR has one that's 
 RS> rated at 9 Amps and .25 VF. They also have one that's 
 RS> rated at 19 Amps and .32 VF. 
.25 do look pretty good. how much do they cost? 
 RS>  
 RS>  Yes, they waste power; but, not THAT much (IMO) and they're 
 RS> simple and reliable. 
agreed .25X9 amp... 2.25watt. 
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