Various diagram

Most cars do not have delayed interior lights. The circuit presented can put this right. It switches the interior lights of a car on and off gradually. This makes it a lot easier, for instance, to find the ignition keyhole when the lights have gone off after the car door has been closed. Since the circuit must be operated by the door switch, a slight intervention in the wiring of this switch is unavoidable. When the car door is opened, the door switch closes the lights circuit to earth. When the door is closed (and the switch is open), transistor T1, whose base is linked to the switch, cuts off T2, so that the interior light remains off. When the switch closes (when the door is opened), the base of T1 is at earth level and the transistor is off.

Circuit diagram:

Capacitor C1 is charged fairly rapidly via R3 and D1, whereupon T2 comes on so that the interior light is switched on. When the door is closed again, T1 conducts and stops the charging of C1. However, the capacitor is discharged fairly slowly via R5, so that T2 is not turned off immediately. This ensures that the interior light remains on for a little while and then goes out slowly. The time delays may be varied quite substantially by altering the values of R3, R5, and C1. Circuit IC2 may be one of many types of n-channel power MOSFET, but it should be able to handle drain-source voltages greater than 50 V. In the proto-type, a BUZ74 is used which can handle D-S voltages of up to 500 V.

Relays ON-delay,? after energizing the relay initiates the timing, in which sophisticated models have an external adjustment via a potentiometer or selector switch. After the expiration of the predetermined time by the user to the switching contacts. Industrial relays are in their majority.

The pneumatic relay delay

Some relays comes with this "delay " , are called timed relays , the former has a kind of " buffer" mechanism , when the coil is energized or not energized . These mechanisms used pneumatic dampers or piston systems with cylinder filled with liquid for shock absorption necessary to slow the movement of the armature . This addition gives the relay delay time of activation, call delay .

The delay relay solid state

The current time delay relays use electronic to generate a time interval circuits , and then energize the relay coil . The electronic timer relays are more versatile than , less prone to failure and time variations with wear mechanical / pneumatic models .

Use timed relay or delay

The use of relays timed or delay is very comprehensive in the industry or even residential , are some utilities to use this device.

As time delay fuse , is a special type of fuse that is designed for specific applications where a delay for shutdown is necessary. It is used in machinery or equipment that consume power surges when connected or give matches , but while using their consumption drop dramatically .

Switch controls two time delay relays are used in conjunction to provide a constant frequency on and off , for sending intermittent power to machines or devices .

Control security wipe before a door of a gas chamber be safely released , an exhaust system must be connected for a certain period of time to " clean up" the chamber of any fumes , poisonous gases , flammable or explosives. A time delay relay in such control provides the time required for cleaning.

Soften the departure of engines , instead of starting in large electric motors , giving full force from the neutral , we can start with low voltage so the engine will be started more smoothly and with less starting current. After a time interval the total energy is applied. See More on relays

Trigger conveyor in sequence , when multiple conveyor belts are arranged to transport material, the straps should be started in the reverse order ( the last before the first ) so that the material does not stack . In order to obtain maximum speed, sometime a circuit delay may be needed on each conveyor belt to give you enough time to reach the speed before being fed time.

The two types of basic delay relays ( on or off )

Basically there are two types of delays relays, DelayRelay On Time and Off Time DelayRelay , ie a relay with delay to turn off and another relay with time- delayed to connect . The relay late to call, or time delay relay On is the most widely used and is referred to most of this text , and also when we talk about delay switch or time delay .

How to delay the electronic signal - Relay Delay Time Homemade

Relay circuit to late to turn, or time delay relay On



First we see a relay circuit to late to turn, or time delay relay on. To delay a pulse we use a timer or timer, it is called Time Delay circuit should work delaying the activation of the relay, so we will have our relay time delay (time Delay Relay). This circuit delay time for relay can be used in most commercially available relays which has a DC voltage of 12 volts and has a coil resistance of 75 ohms or more.

Its operation is simple , when the circuit is energized resistor R2 connected across the supply provides a discharge path for the capacitor when the power is off , the discharge takes advantage of the breakdown voltage Emitter - base of a bipolar transistor . The base junction - reverse emitter connected transistor 2N3904 is used as a zener diode 8 volts that creates a higher turn on voltage for the transistors connected in Darlington configuration that trigger the relay .

In Q3 any bi-polar transistor may be used, but the zener voltage will range from about 6 to 9 volts, depending upon the transistor used. The time delay is 7 seconds , that using a 47K resistor R1 and a capacitor C1 100uF . To reduce the time delay relay simply decreasing the values ​​of R1 and C1. For longer periods of delay , ie to increase the time delay , should place a capacitor with the largest value C1 , the resistor R1 should not be increased.

List of Contents

R1 - Resistor 10 K Ohms 1/4 Watt
R2 - Resistor 47 K Ohms 1/4 Watt
C1 - Electrolytic Capacitor 100uf x 25 Volts
D1 - 1N4001 diode
Q1 - Transistor 2n3052
Q3 and Q2 - 2N3904 transistor
RY1 - Relay 12 Volts

Circuit to relay off delay, or time delay relay Off



The circuit slows down the opening of the relay contacts a short period of time after voltage interruption. The circuit is very simple, a capacitor C1 is charged and the relay is closed when the voltage at the anode of diode D2 rises to 12 volts.

When the voltage is cut off the relay will stay on until the capacitor C1 is fully discharged. The delay time depends on the value of the capacitor, the relay coil current and transistor gain. So to avoid calculations can go testing electrolytic capacitors to obtain the desired delay time.

List of Contents

C1 Electrolytic Capacitor 100uf x 25 Volts
Diode D1 1N4001
D2 Diode 1n4882
Q1 - Transistor 2N2222
RY1 - Relay 12 Volts