Developer page to make a simple, cheap board for TimingLight
Much cleaner and resource (time, ducttape, LED :-) friendly than if everyone solders their own Eiffel-tower type circuits in air.
Base is TimingLight but minor difference:
- flying loom IO, or DSUB (no special connectors)
- 4 channels, in each channel
- 3 throughole LEDs in series
- with some 10 Ohm 1210 size resistors
- ES2J fast 600V diode (same as used for GenBoard/Manual/DDFlyback ) so it can directly trigger from active-low ignition transformer primary (NOT HV secondary!) side
- BC639 throughole NPN (can you suggest an SMD type?) with some base resistor (4k7?) so it can be triggered from an active-high output. Active high input is sometimes needed by ignition modules.
- 2 channels can be connected in parallel for higher light level output, if less than 4 channels are actually needed. Have jumpers for this, or provide airwire recommendation.
The active-high input option makes it possible (see GenBoard/Manual/DDFlyback) to check if injector is actually present and solenoid firing (mechanically it can still be stuck). With no injector present, the injector output voltage can not go above VBatt potential. For this, the timing light ground must be placed to VBatt and an extra battery is needed to power the timinglight board.
- decide if diode is needed before the NPN gate
- decide if something special is useful (eg. LM1815 for one channel)
- decide if 1 or 2 sided (1 could work, but we would likely manufacture it together with 2 layer boards, so no big gains)
- draw the circuit in eagle
- BOM + order necessary components (no long shipping parts, IMHO)
- manufacture the circuit