Pulse Timer Control Relay Circuit

Today we would like to offers solutions for a set time for take control relay and take NO. / NC. contact to apply to control other devices . such as disable or enable the device.

function of this circuit is using IC555 to determine the pulse and a resistor R1 to the period of time.

R1           #Seconds
100k         2
220k         3
470k         6
1M           15

The increase provides more time to increase the value of the Capacitor.

Electronic Part List
R1 = 1 Meg, Preset Pot
R2 = 10K   
R3,R4 = 1K
C1 = 10uF, 16V
C2 = 0.01uF
T1 = BC547 (Gen Purp NPN)
T2 = 2N2222 (Hi Current NPN)
D1 = 1N4001 (Gen Purp Si)
IC1 = 555 (Lo-Power version)
RLA1 = Relay, 9V (amps of your choice)

5 minutes timer delay using cd4093 circuit

This delay timer is a model for the simple circuit. It is the nature of delays, all electrical devices. In the period of 5 minutes.

You can adorn the end of time. If the circuit uses digital IC CD4093 simply too many. And the use of relay driver transistors.

It leads to a change in the situation with electricity or the electric charge of the equipment is. In our electronic circuit used that simple. May are not the problem of the lot. For LED1 to show in animal nutrition nutrition on the circuit. Simply press the user-friendliness S1 easy to use.

Timing = 0.7 C1 x R1

Note.  that R1 has a value of 1M with S1 switch start at position “2″ .This equates to just short of 300 seconds for each position of S1. C1 and R1 through R2 may be changed for different timing periods. The output current from Pin 3 of the timer, is amplified by Q1 (N3904) and used to drive a relay.

DataSheet of DC4093

CD4093B data sheet

9 Sec. Timer control Relay circuit

IC 555 timer output at pin 3 will be high and the voltage at pins 6 and 2 of the timer will be a little less than the lower trigger point, or about 3 Vdc. 

That time the switch is opened, the transistor in parallel with the timing capacitor (22uF) is shut off allowing the capacitor to begin charging and the IC 555 timer circuit to produce an approximate one second clock signal to the decade counter. The counter advances on each positive going change at pin 14 and is enabled with pin 13 terminated low. When the 9th count is reached, pin 11 and 13 will be high, stopping the counter and energizing the relay. Longer delay times can be obtained with most capacitor or most resistor at pins 2 and 6 of the IC 555 timer

Power Off Relay Timer Circuit

      The circuit on the left is a common collector or emitter follower and has the advantage of one less part since a resistor is not needed in series with the transistor base. However the voltage across the relay coil will be two diode drops less than the supply voltage, or about 11 volts for a 12.5 volt input. The common emitter configuration on the right offers the advantage of the full supply voltage across the load for most of the delay time, which makes the relay pull-in and drop-out voltages less of a concern but requires an extra resistor in series with transistor base. The common emitter (circuit on the right) is the better circuit since the series base resistor can be selected to obtain the desired delay time whereas the capacitor must be selected for the common collector (or an additional resistor used in parallel with the capacitor). The time delay for the common emitter will be approximately 3 time constants or 3*R*C. The capacitor/resistor values can be worked out from the relay coil current and transistor gain. For example a 120 ohm relay coil will draw 100 mA at 12 volts and assumming a transistor gain of 30, the base current will be 100/30 = 3 mA. The voltage across the resistor will be the supply voltage minus two diode drops or 12-1.4 = 10.6. The resistor value will be the voltage/current = 10.6/0.003 = 3533 or about 3.6K. The capacitor value for a 15 second delay will be 15/3R = 1327 uF. We can use a standard 1000 uF capacitor and increase the resistor proportionally to get 15 seconds.