Search found 5 matches

by kell
Sat Nov 27, 2004 2:37 pm
Forum: General Discussion
Topic: Melting Point of Plexiglass?
Replies: 33
Views: 6246

Re: Melting Point of Plexiglass?

for heatsinks try the surplus places like
www.allelectronics.com
www.goldmine-elec.com
by kell
Tue Nov 23, 2004 1:34 pm
Forum: General Discussion
Topic: DC Pulse Battery Charger
Replies: 3
Views: 1025

Re: DC Pulse Battery Charger

Put a mosfet or igbt in series with an inductor, running the mosfet off a 555. You can run the whole circuit off ~12 volts. The 555 hard switching the mosfet will cause pulses from the inductor. You need to set the switching on time so that the inductor stays below saturation. Direct the pulses from...
by kell
Sun Nov 07, 2004 5:30 pm
Forum: General Discussion
Topic: Freeze damage proof tube length
Replies: 6
Views: 1424

Re: Freeze damage proof tube length

As you heat copper tubing full of water over an open flame, the tubing will stay at the temperature of the water inside it. In other words, at or below water's boiling point. Plastic tubing inserted in it will also stay at the temperature of the water. If you have plastic that can withstand immersio...
by kell
Sat Oct 30, 2004 10:44 am
Forum: General Discussion
Topic: Timer Question
Replies: 18
Views: 3092

Re: Timer Question

If you use pin 2 to trigger a 555 in monostable mode, pin 2 has to go high again before the pulse ends. This datasheet http://www.fairchildsemi.com/ds/LM/LM555.pdf explains why (top of page 5). You can get various monostable chips that operate different ways. Retriggerable, nonretriggerable, whateve...
by kell
Thu Oct 21, 2004 6:13 pm
Forum: General Discussion
Topic: ignition retard
Replies: 3
Views: 836

ignition retard

My antique bike has a points plate with fixed timing, no weights or springs like a modern breaker. You set the timing to 35 degrees advance (by viewing a mark on the flywheel) and leave it there when riding, it fires there -- at all rpm. I have already replaced the points with hall effect sensors (o...