TLP310xA - High Current Photo Relays

This is relay that produce by Toshiba corporation. This is new high current photo relays that have 3 types. They are called TLP3106A, TLP3107A and TLP3109A. These devices have an off-state output terminal voltage ranging from 30-100V and a steady on-state current of 3.0 to 4.5A in a small 2.54SOP6 package for factory automation and industrial applications. This is the figure of the relays.

Time Manipulator Circuit

This is a design circuit for a type guitar effect. This circuit can be used as delay, reverb or echo because this circuit is use time manipulator. It uses two PT2399 delay integrated circuits to archive up to 600ms delay. Also, with the help of 4 analog switches, the internal configuration of the pedal can change: placing the PT2399 delay chips in series or parallel and adding extra features. This is the figure of the circuit;

Bridging Car Audio Power

The method used in creating bridge audio power in a car.

a. stereo 2 channel bridge into 1 mono channel.The first method of car power audio bridging is combining 2 channel stereo output into 1 mono output to push 1 subwoofer speaker - this is called mono bridging. This means that under normal conditions a 2 channel power is for 2 4Ω speakers. Now, after a mono power cartridge is only to push a speaker, with impedance 2Ω; this of course the power of (rms) power will double. 

Note that the fewer speaker barriers, the power amp rms will increase as well; but with a note that this is also supported by the power amplifier. For example: A 2 channel stereo power amplifier has an output specification of 2x100watt @ 4Ω, bridge mode 1x400w @ 2Ω. This means that if the power is mono cartridge, we can use double coil speakers set to 2Ω, with output power to the speaker by 400 watts. Do you have to play at 2Ω only? The answer depends on the power, if you have stability playing at 1Ω or 4Ω there will certainly be no problem. 

Transistor Relay Driver Circuit

This is a design circuit for transistor relay driver circuit. This circuit is based on BC 548 transistor. This is the figure of the circuit schematic;

Below is the circuit of a relay driver using the NPN transistor BC 548. The relay is connected between the positive rail and the collector of the transistor. When the input signal passes through the I K resistor to the base of the transistor, it conducts and pulls the relay. By adding a 470 uF electrolytic capacitor at the base of the relay driver transistor, a short lag can be induced so that the transistor switches on only if the input signal is persisting. Again, even if the input signal ceases, the transistor remains conducting till the capacitor discharges completely. This avoids relay clicking and the offers clean switching of the relay.

Low Current Relay Circuit

This is a design circuit for low current relay circuit is designed to be used in battery operated electronic devices. Its operating current is in micro amperes (µA). This is done by using a bistable relay and adding some components to force the relay to behave like a mono stable relay. A bistable relay stays at its last state when the power is turned off but consume at least 50mA trigger current. A mono stable relay switches back to its original state when the power is turned off. Here’s the figure of the circuit;

How this circuit can operate? When the power is turned ON, the C1 charges via D1 and the relay coil and this current activates the relay. D1 ensures that the base of T1 is always more positive than its emitter and because of this T1 and T2 are always blocked. Once the power is turned OFF, the emitter of T1 is coupled to the charge voltage at the positive pole of C1. Its base and the relay coil on the other hand are coupled to the negative pole of C1 and now T1 and T2 conduct, C1 can discharge through T2 and relay. The current flows to the relay coil but in reverse order so is activated to its other state. It has the advantage of consuming little current, around 150 µA. For a reliable operation, select the relay’s operating voltage as 2/3 to 3/4 of the main power supply. For example is using a 12V power supply select a 9V relay.

Relay Toggle Circuit Using 555 Timer IC

This circuit is a design for relay toggle circuit. This circuit below toggles a relay when a button is pressed. Pins 2 and 6, the threshold and trigger inputs, are held at 1/2 the supply voltage by the two 10K resistors. When the output is high, the capacitor is charges through the 100K resistor, and discharges when the output is low. When the button is pressed, the capacitor voltage is applied to pins 2 and 6 which causes the output to change to the opposite state. When the button is released, the capacitor will charge or discharge to the new level at the output (pin 3). The parts are not critical, the resistors can be somewhat higher or lower, but the 2 resistors at pins 2 and 6 should be equal values, and the resistor connected to the cap should be 10 times greater or more. This is the figure of the circuit.

Advantages of this circuit are the large hystersis range at the input which avoids false triggering, and only a few parts are needed for construction. One disadvantage is the relay may be engaged when power is first applied. To solve this problem, you could tie the reset line (pin 4) to another resistor/capacitor combination with the capacitor at ground and the resistor at the +V point. This will cause pin 4 to be held near ground for a short period which will reset the output when power is applied. The 100 ohm resistor and 100uFcapacitor serve to filter noise on the supply line if the circuit is used in a automotive application.

8 Channel LPT Relay Circuit

This is a simple design circuit and convenient way to interface 8 relays. This circuit is control using PC. This is the figure of the circuit.

This circuit is using Power Battery Terminal (PBT) for easy relay output and aux power connection. The LED on each channel indicates relay status. Berg pins for connecting power and trigger voltage.