Relay for turning on the rear fog lights. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

Relay for turning on the rear fog lights. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Automobile. Electronic devices

Comments on the article

The relay, the diagram of which is shown in Fig. 1, is designed to turn on and off the rear fog lights of a vehicle in accordance with the algorithm according to UNECE Regulation No. 048.

The rear fog lights are turned on by pressing the locking button once without locking, connected between contacts 3 ("Common") and 5 ("On/Off") when there is supply voltage on contacts 2 ("Fog lights") and/or 6 (" Low beam/high beam") of connector X1 (i.e. if the low or high beam headlights and/or fog lights are on).

The rear fog lights are turned off by pressing the same button once or when the supply voltage is removed from contacts 2 and 6, and if the voltage is reapplied to contacts 2 and/or 6, the rear fog lights do not turn on.

(click to enlarge)

Today, different enterprises have mastered the production of three modifications of the relay: 23.3777 - based on a D-trigger assembled on transistors; on the K561TM2 chip; 22.3777 - on K561TM2IK561TL1 microcircuits.

Each of the modifications has its own advantages and disadvantages. The main advantage of the first two options is simplicity, a small number of parts and their low cost. The main disadvantage of the first relay is low temperature stability due to the use of transistors in the D-trigger. This drawback is absent in the second version of the relay, however, the presence of a flat signal edge can lead to a through current of the microcircuit, which, in turn, during long-term operation of the product causes it and, accordingly, the entire relay to fail.

The main advantage of the third relay option is the steep edges of control signals due to the use of Schmitt triggers, which eliminates the occurrence of through current and thereby ensures high stability of the device as a whole. The main disadvantage is complexity, a large number of elements and their high cost.

Let's look at the third relay option in more detail. The device consists of the following functional units: power unit (diode VD1, zener diode VD2, resistors R2, R6, capacitors C1, C3); control signal conditioner (Schmitt triggers DD1.1 - DD1.3, resistors R1, R3, R4, capacitor C2); initial installation unit (element DD1.4, resistor R5, capacitor C4); trigger (element DD2.1); switch (transistor VT1, diodes VD3, VD4, zener diode VD5, relay K1, resistor R7).

The power supply unit is a parametric voltage stabilizer that provides the necessary power and protection for the relay.

The control signal former performs the functions of protection against unstable switching on/off of the relay due to bouncing of the button contacts and against spontaneous switching on/off of the relay due to interference in the control circuit.

The initial installation unit ensures that the relay is in the off state when voltage is applied to the power unit.

The trigger implements the required device operation algorithm.

The switch, made on electromagnetic relay K1, controlled by transistor VT1, supplies power voltage to the rear fog lights.

When voltage is supplied to contacts 1 and 2 and/or 6 of connector X1, all relay nodes receive power, but the switch is turned off, contacts K1.1 of relay K1 are open. If the voltage is lost at one of these connector contacts, the relay will turn off the rear fog lights that are already on.

When you press the button connected to pins 5 and 3 of connector X1, the trigger changes its state, the switch is activated and turns on the rear fog lights. If you press the button again, the switch and, accordingly, the rear fog lights will turn off.

Timing diagrams of relay operation are shown in Fig. 2. Here tп is the time of supply voltage.

Relay for turning on the rear fog lights

The approximate value is 50...60 ms, determined by the resistance of resistor R2 and the capacitance of capacitor C1; tc is the time the supply voltage is removed. The approximate value is 0,5...1 s, determined by the resistance of resistor R6 and the capacitance of capacitor C1; tdr is the bounce time of the contacts of the button connected between pins 5 and 3 of connector X1. Approximate value - 20...30 ms; Upm is the minimum supply voltage of the K561TL1 and K561TM2 microcircuits. Approximate value - 2...3 V; Uv is the switching voltage of the Schmitt trigger of the K561TL1 microcircuit. Approximate value - 3,6 - 3,8 V; Uo is the switch-off voltage of the Schmitt trigger of the K561TL1 microcircuit. The approximate value is 1,8... 1,9 V.

The device uses both bulk and surface mounted components (resistors and capacitors, with the exception of oxide) mounting. Resistors and ceramic capacitors are of standard size 1206, the oxide capacitor (C1) is aluminum manufactured by HITANO [1]. The relay is protected from polarity reversal of the power source and powerful electromagnetic interference by the high-voltage diode assembly KDS111A2 (VD1) and diode KD243V (VD3).

Field-effect transistor KP501V (VT1) is protected from self-induction voltage when switching relay winding K1 (91.3747 - 10 manufactured by JSC AVAR, Pskov) by a high-voltage diode KD243V (VD4). Microcircuits DD1, DD2 of the K561 series [2] are powered by a parametric stabilizer based on a zener diode BZX55C5V6 (VD2) from PHILIPS [3]. The Zener diode BZX55C7V5 (VD5) from PHILIPS protects the direct output of the DD2.1 trigger from voltage surges “penetrating” through the drain-gate capacitance of the transistor VT1.

The relay (Fig. 3) consists of a casing, a printed circuit board (Fig. 4) on which all elements are mounted, and a six-pin connector for connecting the product to the vehicle’s on-board network (Fig. 5).

Relay for turning on the rear fog lights

The printed circuit board is double-sided, on one side there are elements for surface mounting, on the other - everything else.

Relay for turning on the rear fog lights

Literature

HITANO Aluminum Electrolytic Capacitors. Data Book, 2000.
Integrated circuits and their foreign analogues. Series K554 - K564. Directory. Ed. A. V. Nefedova. - M.: Radiooft, 2000.
PHILIPS SEMICONDUCTORS BZX55 series Voltage regulator diodes. Data Sheet, 1996.

Author: D.Matveev, Cheboksary

See other articles Section Automobile. Electronic devices.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive

LED operation 07.09.2003

The Italian company "Rimsa" starts production of shadowless LED lamps for operating rooms.

Instead of conventional halogen lamps, five bright white LEDs are used, which create an illumination of 50 lux on the operating field a meter away from the lamp (an ordinary 100-watt light bulb gives 25 lux at a distance of a meter, however, mirrors and lenses can increase this value tenfold). Energy consumption compared to incandescent lamps is three times less, the service life is 50 times longer and reaches XNUMX thousand hours.

The LEDs emit no UV or IR light and generate little to no heat, so surgeons do not suffer from heat and the operating field does not dry out.

Other interesting news:

▪ Electric hypercar Lotus Evija

▪ Birch against cholesterol

▪ The brain combines memories

▪ Signal circuit boards found inside human cells

▪ Biometric image sensor based on plastic

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Signal limiters, compressors. Article selection

▪ article Homeric laughter. Popular expression

▪ article Who ordered to build another wall around the besieged city for their own protection? Detailed answer

▪ article Bites of poisonous animals. Health care

▪ article Power unit with low-temperature Stirling engine and vortex tube. Encyclopedia of radio electronics and electrical engineering

▪ article Electrical installations in fire hazardous areas. Electric lamps. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews