for heatsinks try the surplus places like
www.allelectronics.com
www.goldmine-elec.com
Search found 5 matches
- Sat Nov 27, 2004 2:37 pm
- Forum: General Discussion
- Topic: Melting Point of Plexiglass?
- Replies: 33
- Views: 14500
- Tue Nov 23, 2004 1:34 pm
- Forum: General Discussion
- Topic: DC Pulse Battery Charger
- Replies: 3
- Views: 2511
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...
- Sun Nov 07, 2004 5:30 pm
- Forum: General Discussion
- Topic: Freeze damage proof tube length
- Replies: 6
- Views: 3642
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...
- Sat Oct 30, 2004 10:44 am
- Forum: General Discussion
- Topic: Timer Question
- Replies: 18
- Views: 7222
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...
- Thu Oct 21, 2004 6:13 pm
- Forum: General Discussion
- Topic: ignition retard
- Replies: 3
- Views: 2028
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...