Each circuit is a simple well tried design. One uses two transistors in a super-Darlington set-up. The second uses the LM741 op-amp, and the third uses a Schmidt trigger design.
Each board has a PCB-mounted switch to convert the circuit from light to dark switching and vice versa. All board have an SPDT relay output rated to switch resistive loads of up to 2 Amps @ 48Vac or 28Vdc max.Specifications
|Supply||Regulated 12Vdc (Order Code 660.446UK with connector 778.106)|
|Output||1 x SPDT Relay|
|Up to 48Vac or 28Vdc @ 2 Amps max. (Relay Datasheet)|
|Output Connections||NO, NC, C (Relay FAQ)|
|Board Connections||Screw terminal blocks|
|Product Formats||SELF-ASSEMBLY Electronic Kit (KT) Product Formats Info|
|Documentation||3079A User Manual|
3079B User Manual
3079C User Manual
High quality Erp Compliant energy efficient fixed 12V regulated 1000mA max...
A 2.1mm DC power socket with modular terminals for easy use...
Multipurpose black ABS plastic enclosure approx. 83 x 54 x 30mm that can be used to house a number of suitable size kits and modules...
This circuit uses a simple LDR based circuit in super-Darlington set-up to turn on the relay output. A Light/Dark mode switch is used to select either light or dark activation of the relay...
This kit uses the LDR and built-in hysteresis of the 741 op-amp IC circuitry to allow the switch to operate with small and gradual light changes without the problem of relay chatter at the trigger threshold...
This kit uses the LDR and Schmitt trigger circuitry to eliminate the problem of relay chatter at the trigger threshold so that the circuit can be used where the change in light with be small and gradual...