how to make a switch for 230v device using pic ic

Nipuna56 said:

What is L1 and what is the use of Varistor?

Click to expand...

L1 is bulb like load, you can use anything else, like heater element, or something else.

Varistors are often used to protect circuits against excessive voltage by acting as a spark gap and against excessive transient voltages by incorporating them into the circuit in such a way that, when triggered, they will shunt the current created by the high voltage away from the sensitive components. A varistor is also known as Voltage Dependent Resistor or VDR. A varistor’s function is to conduct significantly increased current when voltage is excessive.

https://en.wikipedia.org/wiki/Varistor



You can eliminate varistor from circuit, circuit does not depend on him.

Varistor is used to bypass spikes of some Kilo volts. If 2KVA or 5 KVA spikes come in the power line the varistor acts as a short circuit and bypasses the spike to ground.

What is the wrong of this circuit?

Send circuit as picture if not big problem.

if i click push button bulb work but after release button also bulb work

Try to change Q1 to PNP transistor, collector go to Gnd, and emitter to MOC3041 cathode.

CONT :10A 125 VAC
COIL :5 VDC

What this mean?
what are popular opto couplers ?

Nipuna56 said:

CONT :10A 125 VAC
COIL :5 VDC

What this mean?
what are popular opto couplers ?

Click to expand...

Contacts can handle 10A at 125V AC, and relay coil is for 5V DC.

Popular opto couplers are parts that are often used in electronics designs such as 4N35, CNY serie,....

Optocoupler inside have transistor with base controlled by light from diode, and optocoupler have triac inside which gate is controler by light from diode.





**broken link removed**

https://en.wikipedia.org/wiki/Opto-isolator

now it doesn't work friend

Put for R1 100R.

Do you try this in Proteus or on protoboard. Check all connections.

Proteus
If i try to reduce it's value under 200R and run but error massage appear

What to say if you want to drive car you have two options to play games and to sit in real car and drive.

Get some development board, or buy protoboard for start and practice.

Explain about your water pump;
what is the running current and start current ?
Is it 3 phase or single phase ?
Then we can give you more specific solutions. If you have not yet selected the pump let us know about your pumping requirements; Water flow & height ?

ok friend I tried it thanks friend
1 last thing is this circuit correct?
is it necessary to use R1 resistor?
what are the opto couples that i can use?
is there 5 vdc 250 vac relays?

R1 limit current for diode, you can see in datasheet data.

You dont need to use optocoupler for relay you can use circuits I give you in post #8

Just use NPN or NPN darlington or you can use MOSFet if you want.

Yes, there is 5V 220V but with limited current usually 1A-2A. For often switching and motor use disent relay.
When buying relay always look resistance of relay coil to be higher, later in usage you will have smaller current consuption in circuit.

You can see this web site to expand your knowledge, specially look section about relays
200 Transistors Circuits
http://talkingelectronics.com/projects/200TrCcts/200TrCcts.html

12v RELAY ON 6V SUPPLY
This circuit allows a 12v relay to operate on a 6v or 9v supply. Most 12v relays need about 12v to "pull-in" but will "hold" on about 6v. The 220u charges via the 2k2 and bottom diode. When an input above 1.5v is applied to the input of the circuit, both transistors are turned ON and the 5v across the electrolytic causes the negative end of the electro to go below the 0v rail by about 4.5v and this puts about 10v across the relay.

Alternatively you can rewind a 12v relay by removing about half the turns.
Join up what is left to the terminals. Replace the turns you took off, by connecting them in parallel with the original half, making sure the turns go the same way around