We have for many years been selling our high current light dark sensor circuit and low current light dark sensor circuit which are based around the simple LM741 Light Dark Sensor Circuit for which we provide the circuit design on our website.
During that time we have received many requests for a range of alterations and added features to that basic circuit to make it suitable for a huge range of applications from automated poultry lighting systems to dusk to dawn controllers, and from solar chargers to security systems.
We have now put together one product which pulls together the five most requested features into one easy to use user-programmable unit, the REUK Super LDR Dusk/Dawn Relay Controller which is pictured below:
REUK Super LDR Dusk/Dawn Relay Controller
This product offers five different modes:
Mode 1: On when dark
closes a relay after 3 continuous seconds of darkness, and opens it again after 3 continuous seconds of light.
Mode 2: On when light
closes a relay after 3 continuous seconds of light, and opens it again after 3 continuous seconds of darkness.
Mode 3: On from dusk until dawn
closes a relay at dusk and opens it again at dawn.
Mode 4: On for X hours after dusk
closes a relay at dusk and keeps it closed for a user programmable number of hours after dusk – useful for garden/driveway lighting for example.
Mode 5: Off for X hours after dusk and then on until dawn
at dusk waits a user-programmable number of hours before closing a relay. The relay is then kept closed until dawn. Useful for poultry lighting applications to increase perceived day length – birds roost as normal, but artificial lights can be turned on say 9 hours after dusk for an early dawn in the coop.
This product is supplied in a high quality enclosure and the price (£19.95) includes the pre-wired LDR light detector, and circuit board mounted 16A rated (30VDC or 250VAC) relay. All connections are made to screw-in terminals on the board, and the enclosure is pre-drilled to allow the passage of cables through it to the circuit board.
REUK Mini LDR Dusk Dawn Lighting Controller