Automatic Voltage
What is a relay?
A relay is an electromechanical or electronic device through which a heavy load
can be switched ON & OFF with a nominal input of current & voltage. This article
focuses on electro-mechanical relays used in automotive applications.
How does a relay work?
The utility and function of a relay can be best understood by thinking of a lever.
A lever is inserted at a corner of a heavy load and by placing a wedge (fulcrum)
under the lever, the heavy load can be easily lifted by a small amount of effort.
Similarly, a heavy electrical load drawing heavy current can be switched on & off
by applying a small amount of current through a coil(solenoid). What happens is
this – the coil gets magnetized with the current and attracts or repels a
plunger(a rod passed through the coil). The attracting or repelling of the plunger
either connects two switching contacts in the relay (also known as NO or Normally
Open/Single Throw/Form A) or separates them (NC or Normally Closed/Double
Throw/Form C), as required. As soon as the energisation of the coil is stopped,
the main contacts go back to their original position.
In automobile applications relays of different configurations with single or
multiple contacts are used for different applications.
Why is a relay required?
Apart from switching a circuit with heavy load, on & off, a relay is required to
1. Conserve energy
2. Prolong the life of device
3. Improve the efficiency of a device.
For example let us take the switching of two headlamps of an automobile. If the
same is switched on through a normal switch at the dashboard, the voltage drop
from the battery to the lamps through the switch will be enormous and the heat
generated in the circuit due to resistance will be considerable. The heavy current
will be drawn by the lamps which will not only heat the circuit but also drain the
battery heavily.
To give an example of the effect of voltage drop, a chart is given below:
Operating Voltage. Luminous Intensity of a Lamp. 100% 100% 95% 83% 90% 67% 85% 53%
To switch on a 12V-60/100 Watt Halogen lamp, a typical 12V Relay allows a voltage
drop of only 0.02V and the coil current is only 2 milliamps.
Another important function of the relay is quick switching off(0.05Sec Max.). The
more time the contacts of a switch take to break at full load, the more sparks
will be generated due to electromagnetic effect on contacts in a switched on
state. Prolonged sparking will mean more wear of the contact points and the danger
of contacts melting and generating a fire. International standards have very stringent relay specifications. The endurance of a relay is generally specified in millions of switching operations.
Where should a relay be installed?
Wherever manual switching has been used for direct switching of a Lamp or Motor or
any gadget exceeding 10 Amps of load, a suitable relay must be put in the circuit.
It is best if the relay can be kept as near as possible to the load (but not in a hot area surrounding near the engine)
How should a relay be installed?
1. Wires connected to the manual switch should be connected to any Coil terminal
of the Relay.
2. The load should be connected to any one contact terminal of the Relay (unless
Positive/Negative are specified) and the other to the positive terminal of the
battery (for Negative Ground circuit), with an appropriate Fuse.
For more info on relays and automotive products visit us at
www.fourthgen.net
70 amp Relays, 80 amp Relays, Automatic Diesel Engine Heating Kits, Potentiometer Speed Regulators, Sensors, Timers, Buzzers.
Automatic Cell Phone Battery Charger, Automatic Voltage, Automatic Current
|
|
Cutler Hammer 3-Phase Multi-Voltage Automatic Transfer Switch-320 Amp VT3P320ATS $3,299.99 |
|
|
Monster PRO AVS 2000 Automatic Voltage Stabilizer $1,699.95 |
|
|
*ORIGINAL Stamford MA330 Automatic Voltage Regulator $1,438.00 |
|
|
Monster Power AVS 2000 Automatic Voltage Stabilizer w/ Surge Protection $925.00 |
|
|
$1699.95!!Monster Signature Series AVS2000 AVS 2000 Automatic Voltage Stabilize $850.00 |
|
|
*ORIGINAL Stamford MX321 Automatic Voltage Regulator $900.00 |
|
|
“Bunn” CWTF-3-DV -Dual-Voltage Automatic Coffee Maker (3 lower warmers) $692.34 |
|
|
“Bunn” CWT15-APS Automatic Airpot Coffee Brewer -Dual Voltage 23001.0058 $647.71 |
|
|
Bunn Axiom DV-3 Automatic Coffee Brewer with 3 Lower Warmers – Dual Voltage (Bun $631.21 |
|
|
$1699.95!!Monster Signature Series AVS2000 AVS 2000 Automatic Voltage Stabilize $499.00 |
|
|
Bunn CWTF-TC DV Thermal Carafe Coffee Brewer – Automatic Dual Voltage (Bunn 2300 $600.15 |
|
|
*ORIGINAL Stamford AS440 Automatic Voltage Regulator $541.00 |
|
|
CURTIS 5 ELEMENTS AUTOMATIC DUAL VOLTAGE COFFEE MAKER $475.00 |
|
|
Automatic Voltage Regulator MX321 Stamford Generator $449.00 |
|
|
Automatic Voltage Regulator MX321 Stamford Generator $449.00 |
|
|
Automatic Voltage Regulator MX321 Stamford Generator $449.00 |
|
|
Automatic Voltage Regulator MX321 Stamford Generator $449.00 |
|
|
Automatic Voltage Regulator MX321 Stamford Generator $449.00 |
|
|
Tripplite Htr071u C- Tripplite A/v Ups System With Automatic Voltage $415.96 |
|
|
*ORIGINAL Stamford AS480 Automatic Voltage Regulator $387.00 |
|
|
KEPCO ATE 25-20M POWER SUPPLY Automatic Crossover 0-25V 0-20A High Voltage $345.00 |
|
|
AVR Marathon DVR2000E Automatic Voltage Regulator $350.00 |
|
|
Basler Automatic Voltage Regulator AVR AVC63-12B2 $350.00 |
|
|
GE ENERGY SQ-300i READYPANEL RP1-700-R-00 AUTOMATIC VOLTAGE CONTROL AVC $300.00 |
|
|
Opti-UPS PS1500B, 1500VA 1050W Automatic Voltage Regulator AVR , Refurbished!!! $274.99 |
|
|
Opti-UPS ES1500C-RM 1400VA 980W 1050JOULES Automatic Voltage Regulator AVR $229.58 |
|
|
Opti-UPS ES1500C-RM 1400VA 980W 1050JOULES Automatic Voltage Regulator AVR $229.58 |
|
|
Opti-UPS ES1500C-RM 1400VA 980W 1050JOULES Automatic Voltage Regulator AVR $229.58 |
|
|
Opti-UPS ES1500C-RM 1400VA 980W 1050JOULES Automatic Voltage Regulator AVR $229.58 |
|
|
RV Motorhome Automatic Voltage Protection Smart Sensor 4.0 Pump Device $268.79 |
|
|
AVR VR6 Automatic voltage regulator Generator/Genset part $264.99 |
|
|
AVR VR6 Automatic voltage regulator Generator/Genset part $264.99 |
|
|
Automatic Voltage Regulator R449 $229.99 |
|
|
General Automatic voltage regulator AVR-R450 Generator/Genset part $256.99 |
|
|
General Automatic voltage regulator AVR-R450 Generator/Genset part $256.99 |
|
|
Automatic Voltage Regulator AVR R450 for Generator $252.80 |
|
|
GENUINE MECC ALTE SPA UVR 6 AUTOMATIC VOLTAGE REGULATOR AVR – NEW $250.00 |
|
|
Automatic Voltage Regulator MX321 $229.99 |
|
|
Automatic Voltage Regulator Leroy Somer AVR R450 $249.90 |
|
|
Leroy Somer AVR R450,Automatic Voltage Regulator $229.90 |
|
|
Caterpillar Automatic Voltage Regulator AVR VR6 $246.00 |
|
|
Basler Automatic Voltage Regulator AVR AVC63-12B1 $240.00 |
|
|
Basler Automatic Voltage Regulator AVR AVC125-10B1 $238.99 |
|
|
MINUTEMAN PRO1500LCD PRO1500LCD AUTOMATIC VOLTAGE REGULATOR 1500VA 6BATT BACKUP $238.73 |
|
|
MINUTEMAN PRO1500LCD PRO1500LCD AUTOMATIC VOLTAGE REGULATOR 1500VA 6BATT BACKUP $238.73 |
|
|
Automatic Voltage Regulator R448 $210.00 |
|
|
New Basler automatic voltage regulator AVC125-10-B1 $238.00 |
|
|
Basler AVR AVC63-12B1 AVC125-10B1 Automatic Voltage Regulator $236.00 |
|
|
New Basler AVC125-10B1 Automatic Voltage Regulator $236.00 |
|
|
Basler Automatic Voltage Regulator AVR AVC125-10B1 $236.00 |
|
|
Basler Automatic Voltage Regulator AVR AVC125-10B1 $216.00 |
|
|
MINUTEMAN PRO1100LCD PRO1100LCD AUTOMATIC VOLTAGE REGULATOR 1100VA 6BATT BACKUP $232.33 |
|
|
MINUTEMAN PRO1100LCD PRO1100LCD AUTOMATIC VOLTAGE REGULATOR 1100VA 6BATT BACKUP $232.33 |
|
|
MARELLI Automatic Voltage Regulator AVR M40FA640A $230.00 |
|
|
MARELLI Automatic Voltage Regulator AVR M40FA640A,NEW $229.90 |
|
|
MARELLI Automatic Voltage Regulator AVR M40FA640A,NEW $209.90 |
|
|
Automatic voltage regulator EA63-7 $199.00 |
|
|
Replacement for MARELLI Generator Automatic Voltage Regulator AVR M40FA640A $228.68 |
|
|
Automatic Voltage Regulator AVC63-7 $208.00 |
|
|
New Automatic Voltage Regulator AVC63-7 $225.00 |