Showing posts with label Relay. Show all posts
Showing posts with label Relay. Show all posts
Sunday, 5 March 2017
Solid State Relay Circuit Diagram
Solid state relay is a series that functions like a relay hibryd mechanics. Solid state relays is built with insulating an MOC for separate the input and the switch. With Solid state relays we can avoid the occurrence of sparks as it did in the relay can also avoid the occurrence of conventional connection is not perfect because porous contactor as in conventional relays.
The series of solid state relays This is quite simple and we can make in a PCB hole. For more details can be seen in the picture following a series of solid state relays.
The series of solid state relays This is quite simple and we can make in a PCB hole. For more details can be seen in the picture following a series of solid state relays.
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| Solid State Relay Circuit Diagram |
Solid state relay has many advantages including no mechanical friction on the contactor, the connection process only occur when there are crosses zero, there is no spark at the contactor, not noisy, small konsusi flow control, better endurance.
Wednesday, 11 January 2017
Power Saving Relay Driver Circuit Diagram
This is the Simple Power-Saving Relay Driver Circuit Diagram.In many circuits, the switching action is performed by a relay, which in turn activates an external load. The power consumed by the relay may be unsuitable for battery-powered applications. Here is a simple solution using some inexpensive components to considerably save power.
Circuit and working
Fig. 1 shows circuit diagram of the power-saving relay driver where resistor R1 and transistor T1 form a standard relay driver circuit.
Once the relay is energised, its pole is pulled in to make contact with the N/O side, and it holds in that position with typically 75 per cent of its nominal-rated voltage. Power consumed by a relay coil during this holding time equals V²/R, where R is resistance of the relay coil and V is the voltage. Here resistors R2 and R3, transistor T2 and capacitor C1 lower the power consumption after actuation by applying less than the normal operating power.
Initially, when power is applied, capacitor C1 momentarily shorts resistor R2 and allows full voltage across the relay to pull the pole contact, and then slowly the current through the capacitor drops.
In the meantime, resistor R2 takes care of the current, ensuring it is just sufficient to hold the relay. The constant current mechanism formed by transistor T2 and resistors R2 and R3 effectively drives the relay at very less power.
Following calculations will help us understand how additional circuitry around relay driver transistor T1 saves power. Relay used here is a 12V, 400-ohm sugar-cube type. You can calculate the power saved as shown below:
Nominal current required for the relay (I)= 12V/400 ohm = 30mA
Power consumed by the relay=I2R=0.03A×0.03A×400 ohm =360mW
After introduction of the circuit:
Nominal current required for the relay (I)= 12V/400 ohm = 30mA
Power consumed by the relay=I2R=0.03A×0.03A×400 ohm =360mW
After introduction of the circuit:
The current through the coil (I) =VBE/R2=0.6V/47 ohm=12mA
Power consumed by the overall circuit = V×I = 12×0.012=144mW
Power saved=360mW-144mW=216mW
So, we conclude that considerable power can be saved using the additional circuitry.
This makes it fairly simple for anyone to re-design a relay driver to reduce its power consumption without the use of any expensive components.
An actual-size, single-side PCB for the power-saving relay driver is shown in Fig. 2 and its component layout in Fig. 3.
Switch S1 is used to test the relay driver circuit. You can connect the output of a control circuit, such as a micro controller, to CON2 for controlling the relay circuit.
CON3 helps in connecting to the electrical load. You can connect the load between N/O and pole contacts or N/C and pole contacts.
Fig. 2: An actual-size, single-side PCB for the power-saving relay driver
Fig. 3: Component layout for the PCB
Before connecting the load to CON3, verify the test point voltages given in the table. You
may reduce the value of R1 as per your requirement.
may reduce the value of R1 as per your requirement.
Sourced By: EFY Author: T.A. Babu
Tuesday, 10 January 2017
8 Relay Control Circuit
8 Relay Control Circuit
R1-8=4.7 Kohms T1-8= BD139 (R1-8=15 Kohms if T1-8=BD679)
RL1-8=6V-24V dc Relay D1-8=1N4148
Tuesday, 15 November 2016
Pulse Timer Control Relay Circuit with IC555
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.
Pulse Timer Control Relay Circuit Diagram
R1 #Seconds
100k 2
220k 3
470k 6
1M 15
The increase provides more time to increase the value of the Capacitor.
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)
Pulse Timer Control Relay Circuit Diagram
R1 #Seconds
100k 2
220k 3
470k 6
1M 15
The increase provides more time to increase the value of the Capacitor.
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)
Electronic Temperature Controlled Relay
This temperature controlled relay circuit is a simple yet highly accurate thermal control circuit which can be used in applications where automatic temperature control is needed. The circuit switches a miniature relay ON or OFF according to the temperature detected by the single chip temperature sensor LM35DZ.
When the LM35DZ detects a temperature higher than the preset level (set by VR1), the relay is actuated. When the temperature falls below the preset temperature, relay is de-energized. The circuit can be powered by any DC 12V supply or battery (100mA min.)
Electronic Temperature-Controlled Relay Schematic
How it works?
The heart of the circuit is the LM35DZ temperature sensor which is factory-calibrated in the Celsius (or Centigrade) scale with a linear Degree->Volt conversion function. The output voltage (at pin 2) changes linearly with temperature from 0V (0oC) to 1000mV (100oC).
The preset (VR1) & resistor (R3) from a variable voltage divider which sets a reference voltage (Vref) form 0V ~ 1.62V. The op-amp (A2) buffers the reference voltage so as to avoid loading the divider network (VR1 & R3). The comparator (A1) compares the reference voltage Vref (set by VR1) with the output voltage of LM35DZ and decides whether to energize or de-energize the relay (LED1 ON or OFF respectively).
Components list:
IC1 : LM35DZ
IC2 : TL431
IC3 : LM358
LED1 – 3mm or 5mm LED
Q1 – General purpose PNP transistor ( A1015,…) with E-C-B pin-out)
D1, D2 — 1N4148
D3, D4 — 1N400x (x=2,,,,.7)
ZD1 — Zener diode, 13V, 400mW
Preset (trim pot) : 2.2K (Temperature set point)
R1 – 10K
R2 – 4.7M
R3 – 1.2K
R4 – 1K
R5 – 1K
R6 – 33Ω
C1 – 0.1 µF ceramic or mylar cap
C2 – 470 µF or 680 µF electrolytic cap. (16V min)
Miniature relay – DC12V DPDT, Coil = 400 Ω or higher
Sunday, 13 November 2016
Simple Solar Relay Circuit Diagram
Build a Simple Solar Relay Circuit Diagram.With extended periods of bright sunshine and warm weather, even relatively large storage batteries in solar-power systems can become rather warm. Consequently, a circuit is usually connected in parallel with the storage battery to either connect a high-power shunt (in order to dissipate the excess solar power in the form of heat) or switch on a ventilation fan via a power FET, whenever the voltage rises above approximately 14.4 V. However, the latter option tends to oscillate, since switching on a powerful 12-V fan motor causes the voltage to drop below 14.4 V, causing the fan to be switched off. In the absence of an external load, the battery voltage recovers quickly, the terminal voltage rises above 14.4 V again and the switching process starts once again, despite the built-in hysteresis.
Simple Solar Relay Circuit Diagram
A solution to this problem is provided by the circuit shown here, which switches on the fan in response to the sweltering heat produced by the solar irradiation instead of an excessively high voltage at the battery terminals. Based on experience, the risk of battery overheating is only present in the summer between 2 and 6 pm. The intensity of the sunlight falling within the viewing angle of a suitably configured ‘sun probe’ is especially high precisely during this interval. This is the operating principle of the solar relay.
The trick to this apparently rather simple circuit consists of using a suitable combination of components. Instead of a power FET, it employs a special 12-V relay that can handle a large load in spite of its small size. This relay must have a coil resistance of at least 600 Ω, rather than the usual value of 100-200 Ω. This requirement can be met by several Schrack Components relays (available from, among others, Conrad Electronics). Here we have used the least expensive model, a type RYII 8-A printed circuit board relay. The light probe is connected in series with the relay. It consists of two BPW40 photo-transistors wired in parallel.
The type number refers to the 40-degree acceptance angle for incident light. In bright sunlight, the combined current generated by the two photo-transistors is sufficient to cause the relay to engage, in this case without twitching. Every relay has a large hysteresis, so the fan connected via the a/b contacts will run for many minutes, or even until the probe no longer receives sufficient light. The NTC thermistor connected in series performs two functions. First, it compensates for changes in the resistance of the copper wire in the coil, which increases by approximately 4 percent for every 10 ºC increase in temperature, and second, it causes the relay to drop out earlier than it otherwise would (the relay only drops out at a coil voltage of 4 V).
Depending on the intended use, the 220-Ω resistance of the thermistor can be modified by connecting a 100-Ω resistor in series or a 470-Ω resistor in parallel. If the photo-transistors are fastened with the axes of their incident-angle cones in parallel, the 40-degree incident angle corresponds to 2 pm with suitable solar orientation. If they are bent at a slight angle to each other, their incident angles overlap to cover a wider angle, such as 70 degrees. With the tested prototype circuit, the axes were oriented nearly parallel, and this fully met our demands. The automatic switch-off occurs quite abruptly, just like the switch-on, with no contact jitter. This behavior is also promoted by the NTC thermistor, since its temperature coefficient is opposite to that of the ‘PTC’ relay coil and approximately five times as large.
This yields exactly the desired effect for energizing and DE-energising the relay: a large relay current for engagement and a small relay current for disengagement. Building the circuit is actually straightforward, but you must pay attention to one thing. The photo transistors resemble color less LEDs, so there is a tendency to think that their ‘pinning’ is the same as that of LEDs, with the long lead being positive and the short lead negative. However, with the BPW40 the situation is exactly the opposite; the short lead is the collector lead. Naturally, the back-emf diode for the relay must also be connected with the right polarity. The residual current on cloudy days and at night is negligibly small.
Sourced By: www.streampowers.blogspot.com
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