Dwayne, It's for a model rocket system. Controls the ignition of a second stage and a parachute charge. In air flights will last between 15s and 2 minutes ideally. Used a 9 volt battery before with a 9A peak FET to sink the current works OK, but a 9V battery is pretty heavy. Trying to lighten it up while keeping a small footprint. Thought about using a 12V battery for car alarms but doesn't have enough juice. Ignite time is user controlled via dip switches. So discharge time could range from 15s to 90s. Steve -----Original Message----- From: Dwayne Reid [mailto:dwayner@PLANET.EON.NET] Sent: Monday, March 18, 2002 9:51 AM To: PICLIST@MITVMA.MIT.EDU Subject: Re: [EE]: Current / voltage booster circuit. At 11:41 AM 3/18/02 -0500, M. Adam Davis wrote: >It appears that your circuit would be using this 12 watt supply >infrequently. If so you might consider using one of the solenoid driver >circuits from the data sheets from linear tech. Many of their >regulators are suitable for this. > >The idea is to use a low current supply @ 6 or 12v to charge a >capacitor. When the charge is enough it outputs a high (so your uC >knows when the supply is ready) and you can turn it on via a simple >mosfet or transister circuit. > >Though 6v @ 2a for a second would be a pretty hefty capacitor. Yep - so use a 2nd switcher. Charge a largish capacitor to between 18 & 30 Vdc, then follow that with a switcher to actually generate the 6V. The higher the initial voltage, the smaller the storage cap can be. 30V is about as high as you want to go - most simple switchers have a 35V max input voltage rating. Steve - how much warning time to you have? Do you have to be able to deliver that power pulse instantaneously or can you take 30 seconds to generate and store the charge required? dwayne Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads