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Ac-solid-state-relays – Circuit Schematic
Ac-solid-state-relays
In the case where analog signals are being used as the logic control, hysteresis from a Schmitt-trigger input can be used to prevent haH-wave power output. The...
Low-power-switching-regulator – Circuit Schematic
Low-power-switching-regulator
A simple battery-powered switching regulator provides 5 V outfrom a 9-V source with 80% efficiency and 50 mA output capability. When Q1 is on, its collector vo...
Optoisolated-high-voltage-driver – Circuit Schematic
Optoisolated-high-voltage-driver
This circuit takes as an input a signal from a 5-V CMOS logic circuit and outputs a high voltage of the same polarity. The high-voltage supply can be varied fr...
Switching-regulator – Circuit Schematic
Switching-regulator
The LTC10432 switched-capacitor building block provides nonoverlapping complementary drive to the Ql to Q4 power MOSFETs. The MOSFETs are arranged so that Cl a...
Switching-power-supply – Circuit Schematic
Switching-power-supply
This low-voltage high-current output, sWitching de power supply is running off the 220-Vac input. In this circuit, an ST2 diac relaxation oscillator, Q3, Cl, a...
Ac-relay – Circuit Schematic
Ac-relay
When zero voltage switching is not required, methods of providing this function are illustrated. The lowest parts count version of a solid-state relay is an op...
Dc-latching-relay – Circuit Schematic
Dc-latching-relay
The HllC supplies the de latching relay function and reverse polarity blocking, for currents up to 300 mA, depending on ambient temperature. For de use, the ga...
Solid-state-relay – Circuit Schematic
Solid-state-relay
A higher Iiue voltage can be used if the diode, varistor, ZVS, and power thyristor settings are at compatible levels. ...
Normally-open-and-closed-relays – Circuit Schematic
Normally-open-and-closed-relays
The phototransistor and photodarlington couplers act as de relays in saturated switching at currents up to 5 mA and 50 mA, respectively. When higher currents o...
Normally-closed-half-wave – Circuit Schematic
Normally-closed-half-wave
A normally closed contact circuit that provides zero-voltage switching is designed around the 4N39 SCR optocoupler. ...
Triggering-scr-series – Circuit Schematic
Triggering-scr-series
Snubber circuit R2C2, as shown, might be necessary since Rl and Cl are tailored for optimized triggering and not for dV!dt protection. Fiber-optic pairs can be...
Zero-voltage-switching-circuits – Circuit Schematic
Zero-voltage-switching-circuits
This circuit is effective for lamp and heater loads. Some circuits driving reactive loads require integral cycling and zero-voltage switching-when an identical...
High-voltage-ac-switcher – Circuit Schematic
High-voltage-ac-switcher
A basic circuit to trigger an SCR is shown in Fig. 67 -lA. This circuit has the disadvantage that the blocking voltage of the photon-coupler output device dete...
Burst-power-control – Circuit Schematic
Burst-power-control
Industrial applications sometimes require that power be only briefly applied to a load following the closure of a switch, such as a microswitch or foot switch....
Photoelectric-ac-power-switch – Circuit Schematic
Photoelectric-ac-power-switch
For a dark photocell, high resistance, the vohage across the diac rises rapidly with the line voltage due to the current through C 1, triggering the diac ear...
Laser-diode-pulsers – Circuit Schematic
Laser-diode-pulsers
The laser diode·pulser is a simple drive circuit capable of driving the laser diode with 10-A, 20-ns pulses. For a 0.1 % duty cycle, the repetition rate wil...
Phase-control – Circuit Schematic
Phase-control
This circuit uses a PUT for phases control of an SCR. The relaxation oscillator formed by Q2 provides conduction control of Ql from 1 to 7.8 ms or 21.6° to ...
Who-is-first – Circuit Schematic
Who-is-first
Using two SCRs, this control circuit is designed to lock out the other SCR when one has been triggered, so only one lamp will light. Indicator lamp Il is con...
Totem-pole-driver-with-bootstrapping – Circuit Schematic
Totem-pole-driver-with-bootstrapping
When driving MOSPOWER in a totem-pole output configuration, it is necessary to have the gate voltage 10 to 15 V positive with respect to the source in order ...
Line-synchronized-driver – Circuit Schematic
Line-synchronized-driver
The gate drive that phase controls the four parallel SCRs is accomplished with complementary MOS hex gate MC14572 and two bipolar transistors. This adjustable ...