38. The solid state phase failure relays for three-phase AC phase failure monitoring, protection and control of new devices, referred SSPORR. It is only a five endpoints semico

I tried to design a timer that would do everything it needed to do but with the smallest number of pieces and simplest mode of operation. It only needs the PIC, a four digit LED display, one other IC, a resistor network, one pushbutton switch and a capacitor. It can run on batteries if you use a solid state relay to turn the exposure light on and off thereby adding a minimum of parts to make a fully functional darkroom timer. A simple regulator would add only a few extra parts and allow the use of a "wall-wart" for power.

DC solid state relay (DC-SSR) driving high-power load circuit is shown in (a) below; high power load driving circuit shown in (b) below.

Solid State Relay Switch is a simple kit which will help you control (ON / OFF) a single high power circuit from a low power drive. Load - 24 to 240 VAC @ 500 W. Trigger voltage - 2 to 5 VDC (TTL) @ 10 mA. Input isolated with use of Optocoupler. Power Battery Terminal (PBT) for easy input 230 VAC mains and load connection. Terminal pins for connecting input trigger signal. Heatsink for TRIAC. Four mounting holes of 3.2 mm each. PCB dimensions 29 mm x 74 mm

The basic Idea was to have Christmas lights flash with the music. In my design I use an ordinary amplified computer speaker, a diode bridge, and a ‘CRYDOM’ SSR (Solid State Relay). In order to increase the time that the lights were on as well as protect the SSR I used a Diode Bridge to rectify the signal from the amplifier circuit.”

Flash-back to the 60's with this 5 channel unit with up to 100 watts per channel. This unit uses a PIC16F84 with an 8 bit A/D. The signal from both stereo channels is combined and digitized. Each of 5 frequency bands is processed using a 16 point FFT. Then the level of each channel is output as PWM (pulse width modulation) to a set of solid state relays.

This circuit is basically the same as the 10 channel LED sequencer with the addition of solid state relays to control the AC lamps. The relay shown in the diagram is a Radio Shack 3 amp unit (part no. 275-310) that requires 1.2 volts DC to activate. No current spec was given but I assume it needs just a few milliamps to light the internal LED. A 360 ohm resistor is shown which would limit the current to 17 mA using a 9 volt supply. I tested the circuit using a solid state relay (of unknown type) which required only 1.5 mA at 3 volts but operates up to 30 volts DC and a much higher current.

Below are three examples of controlling a relay from the PC's parallel printer port (LPT1 or LPT2). Figure A shows a solid state relay controlled by one of the parallel port data lines (D0-D7) using a 300 ohm resistor and 5 volt power source. The solid state relay will energize when a "0" is written to the data line. Figure B and C show mechanical relays controlled by two transistors. The relay in figure B is energized when a "1" is written to the data line and the relay in figure C is energized by writing a "0" to the line. In each of the three circuits, a common connection is made from the negative side of the power supply to one of the port ground pins (18-25).

A complete zero-voltage switch solid-state relay contains an input circuit, an output circuit, and the power thyristor. The circuit illustrates a triac power thyristor with snubber circuit and GE-MOVRII Vans tor transient over-voltage protection. The 22 ohm resistor shunts di/dt currents, passing through the bridge diode capacitances, from the triac gate, while the 100 ohm resistor limits surge and gate currents to safe levels. Although the circuits illustrated are for 120-V rms operation, relays that operate on 220 V require higher voltage ratings on the MOV, rectifier diodes, triac, and pilot SCR.

If load current requirements are relatively low (i.e. maximum forward rms current 500 mA), an ac solid state relay can be constructed quite simply by the connection of two H11C optically coupled SCRs in a back-to-back configuration as illustrated.

An SPDT solid state relay is shown. When voltage is applied Ql will turn on, activating load #1, because the full line voltage appears across Q2, supplying gate current through Rl. When SI is closed.

Rl limits input current while Ql acts as a current sink to protect IC1. D1 serves as a polarity protector.

This dark-activated relay switch can be used to turn on walkway or other outdoor lighting at dusk. By using alternate connections to A and B, increasing illumination,

A lot of my projects involve 120VAC, switching relatively slowly. Most people use mechanical relays in that situation, but I don`t like them; I try to avoid moving parts whenever possible. Up to this point, I`ve always used solid state relays. They work really well, but they`re expensive. What this means is that I`ve needed to move my same 2 SSRs

FIG switching solenoid driver circuit, wherein the device chip U8 is 74123, the device is a solid state relays 02, 03, the switching electromagnet coil is sucked PUSH coil, HOL

A Solid State Relay is in reality not a relay after all. There`s no `relay` found, just the electronics circuit which does the switching. It operates a similar way as a relay; it is possible to use a low voltage to switch a higher voltage or better than ordinary relay. This `relay` is placed in. This circuit diagram is quite simple and cheap. Amp

Below are three examples of controlling a relay from the PC`s parallel printer port (LPT1 or LPT2). Figure A shows a solid state relay controlled by one of the parallel port data lines (D0-D7) using a 300 ohm resistor and 5 volt power source. The solid state relay will energize when a "0" is written to the data line. Figure B and C show mechanical

This circuit demands a control current that is 100 times smaller than that needed by a typical optically isolated solid state relays. It is ideal for battery-powered systems. Using a combination of a high current TRIAC and a very sensitive low current SCR, the circuit can control about 600 watts of power to load while providing full isolation and

Switch 50V AC voltage. Maximum drained current will be 5A. Frequency is 50Hz. Switching speed is not important, can be real slow, it is not a problem in my application. I wanted to use solid state relay at first for this purpose. But as soon as I started to search an SSR, I saw that their prices are too high. For a cheaper alternative solution, I want to use MOSFET

Comparison with Electromechanical Relays, Key Components and Internal Structure, AC Output SSRs, DC Output SSRs, AC/DC Input SSRs, Zero-Crossing and Instant-On SSRs, Switching Mechanism, Load Compatibility and Voltage Ratings