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AC-AC SSR Solid State Relay

This is a AC Control Input AC Output SSR Solid State Relay. When a Process Controller has an AC output or a system generates an AC signal of above 100V AC to signal the load to turn on, this device can be used. A BTA40-600 and MOC3041 are used in this.

Fire Retardant SSR Enclosures

A high voltage plastic cap limits current to a bridge which generates a small DC from 230 V AC, this drives MOC3041. The rest is the same. It is better to use a DC control SSR where possible. This AC control SSR is used where only an AC control signal is available. The BTA series has the heatsink tab insulated from the Triac chip inside. The BTB needs electrical insulation to the heatsink.

ac-ac-ssr

Electrical Control Panel Wiring

These devices BTA40600 and MOC3041 make SSR’s very simple. They have proved very reliable and rugged in the field, overrate your designs, use heat sinks and seal the SSR with thermally conductive epoxy. Alumina with ciba araldite without any other filler or dye is the best way to hermitically seal.

Drive SCR thyristor with 555

This circuit gives a burst of pulses to fire 2 SCRs, when pin 4 is taken to 12V the SCR is turned on, to use this circuit you need 12V short pulses phase shifted with respect to AC sine wave on bridge, like this you can control the bridge from near 0% to near 100% ON.

Drive or Fire Thyristors SCR with Pulses

Drive SCR thyristor with 555

Learn about Thyristors here Power Electronics

That way battery banks can be charged, electroplating can be done, current and voltage can be controlled with opamps, thyristors are very rugged compared to transistors and MOSFETS in that order.

+5 to -5 using a 555 Astable Multivibrator

This is a very simple -5V supply using one 555, useful for analog blocks using FET Opamps using low power. This circuit came up when i had to design limited by inventory. It worked well for its need. It converts Positive Five Volts to Negative Five Volts to create a dual supply.

+5 to -5 using a 555 Astable Multivibrator

This +5 to -5 using a 555 Astable Multivibrator.is not a high efficiency design, in fact it cannot take a heavy load. Circuits having some CMOS Opamps and a A/D convertor is ok. Even very small battery designs must avoid this circuit.

Home Made Circuits

This suits well when you want to power an analog amp which has to measure voltages which swing on either sides of zero. It can be used in a LCD based portable measuring instrument running on a rechargeable 9V battery.

Powering a strain gauge amp may be one use, another may be like a RTD temperature meter for -50 to +150 deg C.