Rangkaian Saklar sentuh Berbasis IC 555

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Saklar sentuh Berbasis IC 555

This is the simple circuit of diagram of a small touch using IC NE 555 . This circuit is ideally useful for making touch operated doorbells, buzzers, toys etc which when touched on the touch plate operates the relay for a preset time and the turns off automatically.

the circuit is realized by utilizing the high input impedance of trigger pin of the IC 555. When the IC is triggered by the induced voltage of human body the output goes high for a time determined by R1 and C1. The transistor is used to drive the relay. The relay contacts can be used to drive the load like bell, motor , lights etc.

To setup the circuit connect to power supply and adjust R1 while keeping touching on the touch plate. Stop at the point where relay activates.If relay is in the activated state initially then do the same until the relay is deactivated.

Skema rangkaian saklar sentuh Berbasis IC 555

functions of each pin IC 555

1. Ground, is the input pin of the source of the negative DC voltage
2. trigger, negative input from the lower comparators (comparator B) that maintain oscillation capacitor voltage in the lowest 1 / 3 Vcc and set RS flip-flop
3. output, the output pin of the IC 555.
4. reset, the pin that serves to reset the latch inside the IC to be influential to reset the IC work. This pin is connected to a PNP-type transistor gate, so the transistor will be active if given a logic low. Normally this pin is connected directly to Vcc to prevent reset
5. control voltage, this pin serves to regulate the stability of the reference voltage negative input (comparator A). This pin can be left hanging, but to ensure the stability of the reference comparator A, usually associated with a capacitor of about 10nF to berorde pin groun
6. threshold, this pin is connected to the positive input (comparator A) which will reset the RS flip-flop when the voltage on the capacitor from exceeding 2 / 3 Vc
7. discharge, this pin is connected to an open collector transistor Q1 is connected to ground emitternya. Switching transistor serves to clamp the corresponding node to ground on the timing of certain
8. vcc, pin it to receive a DC voltage supply. Usually will work optimally if given a 5-15V. the current supply can be seen in the datasheet, which is about 10-15mA.

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Rangkaian Driver/Buffer Saklar Relay

type='html'>This is a circuit instead of a standard on-off switch. Switching (Saklar) is very gentle. If we don’t use the PCB, connect unused input pins to an appropriate logic level (’+’ or ‘-’). Unused output pins *NEED* be left open!. One step ’push’ activates the relay, another ‘push’ de-activates the relay.

Rangkaian Driver/Buffer Saklar Relay pIc

list Component Of Rangkaian Driver/Buffer Saklar Relay
R1 = 10K
R2 = 100K
R3 = 10K
R4 = 220 Ohm (optional)
C1 = 0.1µF, Ceramic (100nF)
C2 = 1µF/16V, Electrolytic
D1 = 1N4001
Led1 = Led, 3mm, red (optional)
Q1 = 2N4401 (see text) IC1 = 4069, CMOS, Hex Inverter (MC14069UB), or equivalent
S1 = Momentary on-switch
Ry1 = Relay

Description

This circuit operate on voltages from 3 to 18 volts, but most applications are in the 5-15 volts. Although the IC1 4069 contains protection circuitry against damage from ESD , use common sense when handling this device. Depending on your application you may want to use an IC-socket with IC1. It makes replacement easy if the IC ever fails. The IC is CMOS so watch for static discharge! You can use any type of 1/4 watt resistors including the metal-film type.

The type for D1 in not critical, even a 1N4148 will work. But, depending on your application I would suggest a 1N4001 as a minimum if your relay type is 0.5A or more. Any one in the 1N400x series diodes will work.

Any proper replacement for Q1 will work, including the european TUN’s. Since Q1 is just a driver to switch the relay coil, almost any type for the transistor will do. PN100, NTE123AP, BC547, 2N3904, 2N2222, 2N4013, etc. will all work for the relays mentioned here. For heavier relays you may need to change Q1 for the appropriate type.

For C2, if you find the relay acts not fast enough, you can change it to a lower value. It is there as a spark-arrestor together with diode D1.

For the relay I used an 8 volt type with the above circuit and a 9 volt battery. Depending on your application, if the current-draw is little, you can use a cheap 5V reed-relay type. Use a 8V or 9V relay type if your supply voltage is 12V. Or re-calculate resistor R3 for a higher value.

The circuit and 9V will work fine and will pull the relay between 7 and 9 volt, the only thing to watch for is the working voltage of C2; increase that to 50V if you use a 12V supply.

The pcb was designed for an Aromat/Omron relay, 12V/5A, #HB1-DC12V. You can easily re-design the relay pads on the PCB for the relay of your choice. If you wish to use something you already have, and you don’t want to re-design the PCB, you can glue the relay up-side-down on the pcb and wire the relay contacts manually to the pcb-holes or directly to your application. Use a 2N2222 transistor for Q1 if your supply voltage is higher than 9V and/or your relay is heavy duty, or doesn’t want to pull-in for any other reason.

Again, the pcb drawing is not to scale. Use ‘page-setup’ to put the scale to 103% for a single pcb, vertically, and your scale should be correct. I use a laser printer and so I don’t know if this scale of 103% is for all printers. To check, print a copy onto regular paper and see if the IC pins fit the print. If so, your copy is correct. If not, change the scale up of down until a hardcopy fits the IC perfectly.

The Led is nice for a visual circuit indication of being ‘on’. For use with 12V supply try making make R4 about 330 ohms. The LED and R4 are of course optional and can be omitted. Your application may already have some sort of indicator and so the LED and R4 are not needed.

Rangkaian Saklar Sentuh

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This is a Turn on and turn off your electrical devices using touch switch, so you can “play” your electronic devices more fun. Touch switch don’t need mechanical part, so they will not worn out due to mechanical contact. Touch switches can be used in places where regular switches would not last, such as wet or very dusty areas. You just need to add some relay to switch your devices which require high voltage supply.

Skema rangkaian saklar sentuh

Component list:

C1: 10uF/16V Electrolytic Capacitor
R1, R2: 100K 1/4 Watt Resistor
R3: 10 Meg 1/4 Watt Resistor
U1: 4011 CMOS NAND Gate IC
MISC 1 Board, Wire, Socket For U1


Notes:

• The contacts an be made with just two loops of wire close together, or two squares etched close together on a PC board.
• When activated, the output of the circuit goes high for about one second. This pulse can be used to drive a relay, transistor, other logic, etc.
• You can vary the length of the output pulse by using a smaller or larger capacitor for C1.

IC 4011 Description:

The HEF4011B provides the positive quadruple 2-input NAND function. The HEF4011 have equal source and sink current capabilities and conform to standard B series output drive.
The devices also have buffered outputs which improve transfer characteristics by providing very high gain. All inputs are protected against static discharge with diodes to VDD and VSS.

The HEF4011B Features

Low power TTL: Fan out of 2 driving 74L compatibility: or 1 driving 74LS
5V–10V–15V parametric ratings
Symmetrical output characteristics
Maximum input leakage 1 μA at 15V over full
temperature range.
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