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Showing posts with label relay. Show all posts

Saturday, October 25, 2014

Energy Saver Relay Coil Diagram Circuit

Some relays will become warm if they remain energized for some time. The circuit shown here will actuate the relay as before but then reduce the ‘hold’ current through the relay coil current by about 50%, thus considerably reducing the amount of heat dissipation and wasted power. The circuit is only suitable for relays that remain on for long periods. The following equations will enable the circuit to be dimensioned for the relay on hand: R3 = 0.7 / I Charge time = 0.5 × R2 × C1 Where I is the relay coil current. After the relay has been switched off, a short delay should be allowed for the relay current to return to maximum so the relay can be energized again at full power. To make the delay as short as possible, keep C1 as small as possible. In practice, a minimum delay of about 5 seconds should be allowed but this is open to experimentation.

Circuit diagram:

Relay Coil Energy Saver Circuit Diagram

The action of C2 causes the full supply voltage to appear briefly across the relay coil, which helps to activate the relay as fast as possible. Via T2, a delay network consisting of C1 and R2 controls the relay coil current flowing through T1 and R3, effectively reducing it to half the ‘pull in’ current. Diode D2 discharges C1 when the control voltage is Low. Around one second will be needed to completely discharge C1. T2 shunts the bias current of T1 when the delay has elapsed. Diode D1 helps to discharge C1 as quickly as possible. The relay shown in the circuit was specified at 12 V / 400 ohms. All component values for guidance only.

Author: Myo Min - Copyright: Elektor July-August 2004

Thursday, October 16, 2014

Make Relay Based Motorcycle Alarm Circuit Diagrams

You can Make Relay Based Motorcycle Alarm Circuit Diagrams. You can use them to protect your motorcycle - but they have many more applications. If you use relays with 6-volt coils - theyll protect your "Classic Bike". Both alarms are very small. The completed boards occupy about half a cubic-inch - 8 cc. The standby current is zero - so they wont drain your battery.

Relay Based Motorcycle Alarm Circuit Diagram 1 uses a SPCO/SPDT relay - but you really only need to use a SPST relay. If you are going to use the veroboard layout provided - youll need to use the style of relay specified. But you can build the alarm using whatever style of relay you have available.

Relay Based Motorcycle Alarm Circuit Diagram 1

Any number of normally-open switches may be used. Fit the mercury switches so that they close when the steering is moved or when the bike is lifted off its side-stand or pushed forward off its centre-stand. Use micro-switches to protect removable panels and the lids of panniers etc. When one of the trigger-switches is closed - the relay will energize and the siren will sound.

You can choose what happens next. If you build the circuit as shown, the siren will continue to sound until you turn it off - or until the battery is exhausted. But, if you leave out D3 - the siren will stop sounding immediately the trigger-switch is re-opened.

While youre within earshot of your machine - the former configuration is best. You can always turn off the alarm yourself. But if you are going to be away from your bike for any length of time - and you dont want to cause a nuisance - then the latter configuration is probably more suitable. If you include a SPST switch in series with D3 - you can select the behaviour that best suits the circumstances at any given time.

Relay Based Motorcycle Alarm Circuit Diagram 1a

Relay coils and some sounders produce high reverse-voltage spikes that will destroy sensitive electronic components. D1 and D2 are there to short-circuit these spikes before they can do any damage. Although there is nothing in the alarm circuit itself that could be damaged - I have no idea what other electronic equipment might be connected to the same power supply. So I included the two diodes as a precaution. If youre satisfied that theres nothing on your bike that might be damaged in this way - you can leave out the two diodes.

Relay Based Motorcycle Alarm Circuit Diagram 2 uses a DPCO/DPDT relay - but you really only need to use a DPST relay. If you are going to use the veroboard layout provided - youll need to use the style of relay specified. But you can build the alarm using whatever style of relay you have available.

Relay Based Motorcycle Alarm Circuit Diagram 2

You can choose what happens next. If you build the circuit as shown, the siren will continue to sound until you turn it off - or until the battery is exhausted. But, if you leave out the (yellow) solder-bridge in the top left-hand corner of the diagram - the siren will stop sounding immediately the trigger-switch is re-opened.

While youre within earshot of your machine - the former configuration is best. You can always turn off the alarm yourself. But if you are going to be away from your bike for any length of time - and you dont want to cause a nuisance - then the latter configuration is probably more suitable. Connect a SPST switch in place of the (yellow) solder-bridge - and you can select the behaviour that best suits the circumstances at any given time.

Relay Based Motorcycle Alarm Circuit Diagram 2 a

Whichever alarm you build - the circuit board and switches must be protected from the elements. Dampness or condensation will cause damage. Without the terminal blocks - the board is small. Ideally, you should try to find a siren with enough spare space inside to accommodate it. Fit a 1-amp in-line fuse as close as possible to the power source. This is Very Important. The fuse is there to protect the wiring - not the circuit board. Instead of using a key-switch you can use a hidden switch; or you could use the normally-closed contacts of a small relay. Wire the relay coil so that its energized while the ignition is on. Then every time you turn the ignition off - the alarm will set itself.

When the alarms are not sounding - the circuits use no current. This should make them useful in other circumstances - where a power supply is not readily available. Powered by dry batteries - with the relay and siren voltages chosen to suit - the alarms could be fitted almost anywhere.

Sourced By : Streampowers

Simple Sound Activated Lamp Relay Switch

This simple Sound-Activated Lamp circuit shown int the schematic diagram actives the switch using sound. We can use this circuit for various applications, such as automatic (sound-controlled) disco light or car’s LED light show. The Q1 amplify the audio from mic. The R1 is used to adjust the peak of signal to greater than about 0.7 volts, act as sensitivity adjuster. A certain level, the signal coming from microphone, after amplification by Q1, will trigger the SCR and light lamp I1. If we change the lamp with a relay, then we can get a sound-activated relay/switch, which can be used to control more powerful / high wattage high voltage lamps. If we use a relay, place a 1N4007 diode in parallel with the relay coil to prevent the back-emf from relay coil destroying the SCR.

Sound-Activated Lamp Circuit Diagram

Sunday, August 10, 2014

Relay Delay circuit

This is a relay delay schema.By using this schema we can delay the function though schema gave the signal.That means there is some time to operate the relay after the signal which gave form the schema.here you can get 6 second delay.But if you want more you can do it changing the value of capacitor.If you use 470uf it will delay 20 seconds.

Note

# Use 12v to operate this schema.
#If you use this schema for your vehicle Please cover this schema properly.