Here is a hobby circuit of a multi channel remote control system, by which you can control 8 different appliances. The main sections of this multi channel remote control circuit are the RF receiver and transmitter. By using this circuit we can control 8 devices, each of them independently by pressing the push buttons. When the button is pushed, corresponding relay is turned ON and is turned OFF on the next push. Here the relay load current is dependent on the relay used. A serial encoder IC HT12E and a serial decoder IC HT12D are used, where the encoder IC encodes the parallel data to serial and decoder IC decodes the serial data to parallel during the wireless transmission.
You must need a regulated power supply of 5 volt for this circuit because ICs 7476 and 74138 requires 5v for its operation. The main advantage of this system is that it does not require a ‘line of sight’ as compared to IR remote control systems; also it gives longer distance control.
Circuit diagram of RF remote control
RF Transmitter
RF Reciever
Device driver
Components
- RF Transmitter Module 434Mhz
- RF Receiver Module 434Mhz
- IC HT12E
- IC HT12D
- IC 7476 4Nos
- IC 74138
- Push button 8Nos
- Relay 12V,10A 8Nos
- IC 74174
- Transistor BC548
- Resistor (750K,33K,1k 8Nos)
Working
- Maximum voltage of TTL ICs is 5v. So we are using a 7805 voltage regulator IC which provides 5V output.
- 74147 is the priority encoder IC which generates the BCD corresponding to the pressed switch.
- It is given to the serial encoder IC HT12E which converts the parallel BCD value to corresponding serial data to transmit through the RF transmitter.
- The RF Transmitter transmits the serial data and RF receiver receives the serial data, both operates on 434Mhz.
- It is given to the serial decoder IC HT12D which converts the serial data to parallel.
- It is again decoded by a 3 to 8 decoder IC 74138 to operate the relay.
- Output of 74138 is the clock of JK flip flop IC 7476 which operates in toggling mode. (i.e. if one clock is received it inverts the output, thus it turns OFF the relays).
Components Pinout
RF Transmitter Module RF Receiver Module
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i'm trying to build this circuit. but before that i want to simulate the circuit. the problem is there is no ht123 and ht12d ic in any of the simulation sofware, is there any way to directly connect the transmitter circuit to the receiver? this project is cool btw. thanks
ReplyDeleteHi LunaeMaster
DeleteYou can connect the DOUT pin of IC HT12E in the transmitter section to the DIN pin of the IC HT12D in the receiver, then you ca check it without transmitter and receiver modules
thanks for tip. sorry for being a noob, but i can find ic ht12d and ht12e in any of my simulation software. is there any way to connect them both? or you had already simulate this circuit. if so can you mail me the diagram. i'm a student, and my year project needs me to simulate the circuit first.
DeleteHi LunaeMaster
DeleteI have no simulation of this circuit,but i tested this circuit already. if any problem with this i will help you.
if you want simulate this you can connect PIC controllers in place of serial encoder and decoder ICs.
This comment has been removed by a blog administrator.
DeleteHi,
DeleteUnfortunately by a typing mistake your last question was deleted, Anyway here is the question and answer.
Question: ok i think i can go on through that. lets say i want to use only three devices ie three switches, may i know which switch is controlling which relay and is it ok if i reduce the switches. also what the extra switch are for? another one, in case the simulation is needed, is there a way to directly connect the outputs of ic 74147 to ic 74138?
bAnswer: If you need to control only three devices, there in no need of 74147 and 74138 ICs. You can connect switches directly to HT12E encoder IC and the flip flops to decoder IC HT12D. In case you need to turn ON the device only when the switch is pressed, you can remove 7476 also.
Switches details:
IC HT12E IC HT12D
pin 13 = pin 13
pin 12 = pin 12
pin 11 = pin 11
pin 10 = pin 10
ok, i can make sense of that. one more question, my controlled device is a servomotor. i want it to be like on the first button push the motor spins clockwise, and the next push, the motor spins anti-clockwise. i have a vague understandings in flip flops, i want to know which IC 7476 pin will do the command like i said. thanks
ReplyDeleteHi LunaeMaster
DeleteIt is complex to spin motor in both direction using flip flops, you can use IC L293D for that, for more details refer this link Bidirectional motor control
great, this solve many of my problems. thanks
DeleteHi,
DeleteGlad to know your problems were solved. By the way, don't forget to follow us on facebook,google plus and subscribe us. All the best and keep visiting.
for that bubble,did i need to connect inverter(ic 7404) ?
ReplyDeleteHi Angen,
DeleteThose pins are already inverted within the IC. No need for external inverter.
All the components are available in Delhi market in which place ?
ReplyDeleteAnd the ckt works properly after completing ?
And what is the full name of IC 74147 i thinks they are two types ?
Hi Amit,
Delete1)All the components used here are commonly available. Sorry we don't know about the availability of the components at your locality. You can buy them online.
2)It will work. We can help you if you come across any problem. Build the circuit section by section, then you can troubleshoot each section easily.
3)74LS147
made this circuit,not working.kindly guide checking of circuit step by step
ReplyDeleteFirstly you connect DOUT pin of HT12E directly to DIN pin of HT12D ,then connect GND and VCC to data pins of HT12E and check if it's received at the data pins of HT12D by using a LED.
Delete