This is a Pulse timer, also known as a ‘bistable timer’. When the timer is triggered by applying power to +- 12v terminals the timer will switch ON & OFF (pulse). The ON time is set by VR2, the OFF time is set by VR1. This pulsing will continue until power is removed from +- 12v terminals.
The timer is started by applying power to the +- terminals as shown in the drawing below. The pulsing ON/OFF will continue until the power is removed. Adjustment of the pulse is as follows. To increase the OFF time turn the Variable Resistor VR1 to the right (clockwise), to increase the ON time turn the variable resistor VR2 to the left (anticlockwise). The output relay will be energised during the ON period (pulse). The relay has two sets of changeover contacts, this means that in the OFF (pause) state there is a circuit between the COM and NC terminals, and in the ON (pulse) state there is a circuit between the COM and NO terminals. The Green LED behind the Variables will indicate when the timer is in the PULSE state and will be Off during the PAUSE state, use this indication to set the timer
Size of the Timer.
The timer board is 59 x 33mm and has a height of 15mm. There are 4 fixing holes one in each corner of 4mm. This will accept our range of self adhesive PCB mounts or M3 screws.
Simple Red /Green Flashing LED.
If the Pause and Pulse are set the same then the Green will be ON for the Same Period as the Red.
By using a High Bright white LED and increasing the pause to a few seconds, and reducing the pulse to a flash you have a Lighthouse Beacon.