Circuit Progress
- Research and thinking about the circuit.
- Purchased more parts, and fried another 7515 (these things are really fragile ... they won't handle anything over 1A very well, or at all !)
- Learned further about high power darlington transistors (very high hFE switching ... so seemingly very twitchy on small or "start up" loads).
- Bought more parts (including spares ... in case 555 circuit is required for timing)
- Got the timer circuit to run (hooray !) working on full 42V. Might be too slow to start up on lower voltage ?
- Figured out I can use a "button press" to short the circuit, and turn it off.
- Confirmed by measurement, that once turned off ... absolutely 0A draw (of course !).
- Recreated schematic, very readable !
- Discovered a better relay (shorter ... fit in box better ... and same power).
- Created the schematic and pinout (to scale) in Target 3001.
- Installed it in the schematic, and discovered a potential mistake.
- Completely finished the new version of the schematic, and PCB.
Need to Buy
- Part SY4062 - being DPDT relay, 5A, $5.95 ... model FRF6 relay, spec sheet here: http://www.ficrelay.com.hk/details/FRS6.pdf
Corrected Schematic, and PCB
Circuit Progress
- Research and thinking about the circuit.
- Purchased more parts, and fried another 7515 (these things are really fragile ... they won't handle anything over 1A very well, or at all !)
- Learned further about high power darlington transistors (very high hFE switching ... so seemingly very twitchy on small or "start up" loads).
- Bought more parts (including spares ... in case 555 circuit is required for timing)
- Got the timer circuit to run (hooray !) working on full 42V. Might be too slow to start up on lower voltage ?
- Figured out I can use a "button press" to short the circuit, and turn it off.
- Confirmed by measurement, that once turned off ... absolutely 0A draw (of course !).
- Recreated schematic, very readable !
- Discovered a better relay (shorter ... fit in box better ... and same power).
- Created the schematic and pinout (to scale) in Target 3001.
- Installed it in the schematic, and discovered a potential mistake.
- Completely finished the new version of the schematic, and PCB.
Need to Buy
- Part SY4062 - being DPDT relay, 5A, $5.95 ... model FRF6 relay, spec sheet here: http://www.ficrelay.com.hk/details/FRS6.pdf
