It sounds like a good plan. That is how I got started designing chargers. I looked at what was available and used the best and discarded the rest.
I would love to buy a new PFC-20 also. I have Beta #1. The new ones have: -an improved buck/boost mode switch that makes significantly less noise, -better thermal management to have a longer hang time in hot ambients, -a variable speed fan that ramps up instead of a digital hi/low switch, -the buck enhancer option to put out 50% more power at low pack voltages, -a double pole breaker to turn off BOTH lines coming into the charger, -an improved EMI filter on the input. -the controls on the end instead of on the top. -mounting flanges (mine has none), -better power factor at low pack voltage, -higher temperature rated inductor hold downs, -improved overcurrent protection for the power transistors. -more efficient rectifier bridge -larger power traces on the circuit board, -better Regbus implementation, -better timer options (includes zero time), -better LED indicators, -remote control port. I should not complain too much, this unit will put out 6 kW off 240 VAC into a 360 volt pack. That does not help me charge my 48 volt car. Using the buck enhanced PFC-50 at Woodburn was a real kick. It put 72 amps into my car from a 20 amp 240 VAC feed. Bulk charge lasted only 6 minutes and it tapered down to 2 amps in about 15 minutes. Joe Smalley Rural Kitsap County WA Fiesta 48 volts NEDRA 48 volt street conversion record holder [EMAIL PROTECTED] ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, October 08, 2002 8:49 AM Subject: Re: Tropica update/charger chip. > Joe, > Thanks for the comments. I have 2 Tropica chargers and my trusty Fair Radio box so my car won't be down. My plan was to do a small perf board just above the existing board. Instead of removing the bq2003 physically, I was going to disconnect it from driving the charger by removeing a couple of resistors. This would open the FET control and unload the sense lines. The perf board would contain the additional parts to set switching freq, status LEDs, and the new voltage dividers for current and voltage sense. The sense inputs are a bit different between the bq2003 and bq2031. I'd try and keep the connentions to the main board very short to keep the noise down. I think I have the test equipment I need although my DVM isn't true RMS. > > Is the education worth it? Maybe you should ask that afterwards! I've love to be able to send Rich a check for one of the PFC units but right now, I can't afford it. > > thanks, > Steve
