How to connect a relay through an optocoupler homemade. Then consider using a latching relay and explore using a pchannel or an nchannel mosfet. Warning this manual is intended for qualified service personnel only. The following post describes how to drive a relay by using an isolated method, or through an optocoupler device. In this 4channel relay driver circuit we have used an optocoupler whic his triggered by active low signal, to trigger the npn transistor which further drives the relay. Ground rod driver puller p74144 51200101676 51200101676. Optocouplers and optoisolators can be used on their own, or to switch a range of other larger electronic devices such as transistors and triacs providing the required electrical isolation between a lower voltage control signal, for example one from an arduino or microcontroller, and a much higher voltage or mains current output signal. Here we have used 12v 10amp relay in this pcb board, but you can also use 5v relays. Circuit options explore issues, solutions for relay drivers. Relay coil and sensitive logic circuits optimized to switch relays of 12 v rail capable of driving relay coils rated up to 6. The wellestablished relaydriving circuit uses an optocoupler to isolate the grounds and noise coupling between the lowvoltage digitalcontrol signal circuit.
The driven relay can then operate as a switch in the circuit which can open or close, according to the needs of the circuit and its operation. The phototransistor can be used to switch current in the output circuit. Top 5 elctronic project with bc547 transistor, tri ac, rgb led, photo diode duration. Optocoupler tutorial about how optocouplers and optoisolators use light to. I have some optocouplers to isolate mcus power and power supply for the relays to control leds, dc and ac drivers. I have a question about controlling relays by using optocoupler. The circuit shown in figure 1 will drive the relay through optocoupler in same circuit with same power supply. To reduce the risk of electric shock, fire or injury, do not perform any servicing other than that contained in the operating instructions unless you are qualified to do so. As shown in the following circuit diagram, the relay driver may consist a npn transistor or a pnp transistor.
You can keep improving your circuit, like adding an optocoupler, and play with the circuit to turnonoff the relay using a high or low digital signal from. These simple optocoupler relay driver circuits can be used in variety of electronic projects. The question was asked by one of the interested members of this blog, miss vineetha. Im wanting to control two 12v relays by means of an npn transistor, and will.
A relay driver circuit is a circuit which can drive, or operate, a relay so that it can function appropriately in a circuit. How to make an 8 channel relay driver board optically isolated. This page is intended to be a reference list of basic specifications for electronic test equipment, especially obsolete models. How to use optocoupler and triac to control ac load. I have been collecting this information for about 25 years, starting with a well thumbed tucker electronics catalog, and then adding listings from other catalogs, other web sites, and of course ebay listings. Pmc circuit card implementing data bus protocols including arinc429, milstd1553 and rs422. Here is a simple microcontrollerrelay interface circuit with perfect galvanic. Fused biconic taper polarization maintaining coupler glass fusion tower home made assembled at galileo electro optics corp 1987. Typical relay current driver circuit use an optocoupler connected to a transistor which then drives the relay. Driving relay directly from optocoupler, what is best.