THE SECOND “LIFE” OF BEACON

Flashing beacons are used in electronic home security systems and in cars as devices of indication, alarm and warning. Moreover, their appearance and “stuffing” are often not distinguished from beacons (special signals) emergency and operational services.

On sale are classic indicators, but their inner “filling” is striking in its anachronism: they are made on the basis of a powerful lamp with a rotating Chuck (a classic of the genre) or lamps of the type IFK-120, IFCM-120 stroboscopic device that flashes at equal intervals of time (pulse lights). Meanwhile, in the XXI century, when there was a triumphal procession very bright (powerful light) LEDs.

 

One of the fundamental points in favor of replacing incandescent and halogen lamps with LEDs, in particular in the flashing lights are the larger resource (uptime) and the lower cost of the latter.

 

The led chip is practically “Neubauer”, so the resource unit mainly determines the durability of the optical element. The vast majority of manufacturers use to manufacture various combinations of epoxy resins, of course, with different degrees of purification. In particular, because of this, LEDs have a limited resource, after which they begin to get cloudy.

Different manufacturers (do not let them free advertising) claim the resources of their LEDs from 20 to 100 thousand (!) hours. The last figure I do not believe, because the led needs to work continuously for 12 years. During this time, turn yellow, even the paper on which the printed article.

 

However, in any case, in comparison with the resource of traditional incandescent lamps (less than 1000 hours) and gas discharge lamps (up to 5000 hours), led by several orders of magnitude more durable. Obviously, the key to a great online is providing a favorable thermal regime and a stable power supply LEDs.

 

 

Fig. 1. Circuit diagram led beacon

 

The predominance of powerful LEDs with a luminous flux of 20 — 100 LM (lumens) to the latest electronic devices industrial manufacturing in which they work instead of incandescent lamps, provides a basis and Amateurs to use these LEDs in their designs. Thus, I am bringing the reader to think about the possibility of replacing emergency and special lights various lamps high-power LEDs. The current consumption of the device from the power source will be reduced and will largely depend on the applied led. For use in the car (as a special signal, emergency light pointer and even “emergency stop sign” on the roads) the current consumption is unimportant, since the battery (battery) car has quite a lot of energy (or more 55 Ah or more). If the beacon is powered by an independent source, the current consumption of the installed inside the equipment will be important. By the way, the vehicle battery without charging may discharge during continuous operation of the beacon.

 

For example, the “classic” beacon operational and emergency services (blue, red, orange, respectively) when powered by DC 12 V consumes more than 2.2 A, which consists of consumption of the electric motor (torque cartridge) and the lamp. When operating the pulse flash light current consumption is reduced to 0.9 A. If instead a pulsed scheme to collect led (see below), the current consumption will be reduced to 300 mA (depends on the power of applied LEDs). Savings in the cost of parts is also notable.

 

The above data is established by the author experimentally (only tested six different classic flashing lights).

 

Of course, not studied the question of the power of the light (or rather, its intensity) from those or other flash devices, because the author has not had and does not have special equipment (luxometer) for this test. But due to the innovative solutions proposed below, the issue becomes secondary. Even relatively weak light pulses (particularly from LEDs), passed through the prism of inhomogeneous glass cap light at night is more than enough for the tracker noticed for a few hundred meters. It is in this sense far warning, wouldn’t you say?

Now consider the electrical circuit of the “substitute bulbs” flashing beacon (Fig. 1).

 

This electrical schematic diagram of the multivibrator can be called simple and affordable. The device is designed based on the popular IC timer КР1006ВИ1 containing two precision comparator providing the error comparison voltage of at least ±1%. The timer was repeatedly used by radio Amateurs to build such popular schemes and devices, such as relays, multivibrators, inverters, detectors, comparison voltage, and others.

 

The structure of the device, except for the integral timer DA1 (multi-chip КР1006ВИ1), consisting of oxide of timing capacitor C1, a voltage divider R1R2. C3 IC output DA1 (current up to 250 mA) control pulses are applied to the LEDs HL1—HL3.

 

The principle of operation of the device

 

The inclusion of the tracker is done using the switch SB1. The principle of operation of the multivibrator is described in detail in the literature.

 

For the first time at pin 3 chip DA1 high level voltage and the LEDs light up. Oxide capacitor C1 begins to charge through the circuit R1R2.

 

After about one second (time depends on the resistance of the voltage divider R1R2, and the capacitance of the capacitor C1, the voltage on the plates of the capacitor reaches the magnitude required to trigger one of the Comparators in a single package chip DA1. The voltage at pin 3 chip DA1 is set to zero and the LEDs extinguish. This continues in a loop until the device is supplied voltage.

 

Also indicated in the diagram, as HL1—HL3 recommend the use of high-power LEDs HPWS-T400 or similar with current up to 80 mA. Can be applied to only one led from the series LXHL-DL-01, LXHL-FL1C, LXYL-PL-01, LXHL-ML1D, LXHL-PH01,

 

LXHL-MH1D production Lumileds Lighting (orange and krasnooranzhevy colors glow).

 

The supply voltage of the device can be reduced to 14.5 V, then it can be connected to on-Board automobile network even with the engine running (or rather generator).

 

Design features

 

Board with three LEDs is installed in the case of beacon is “heavy” nominal design (lamps with a rotating cartridge and motor).

 

To the output stage had more power, you will need to set the point a (Fig. 1) current amplifier transistor VT1 as shown in figure 2.

 

 

Fig. 2. Connection of the auxiliary amplifier circuit

 

After such a refinement can be applied to three parallel connected led types LXHL-PL09, LXHL-LL3C (1400 mA),

 

UE-HR803RO (700 mA), LY W57B (400 mA) — all orange. The total current consumption will increase accordingly.

 

The variant with flash

 

Who preserved details of the cameras with built-in flash, one can go the other way. To do this the old lamp-the flash is removed and connected in circuit as shown in figure 3. With the presented Converter, connected also to the point a (Fig. 1), the output of the device with the lowest voltage will receive the pulses with an amplitude of 200 V. the Voltage in this case is clearly increase to 12 V.

Output pulse voltage can be increased by including in the circuit of several Zener diodes, for example, VT1 (Fig. 3). This silicon planar Zener diodes to stabilize the voltage in DC circuits with a minimum value of 1 mA and power up to 1 watt. Is indicated in the diagram, you can use Zener diodes КС591А.

 

 

Fig. 3. Wiring diagram for flash lamp

 

The elements C1, R3 (Fig.2) comprise a damping RC-chain, damping the high frequency oscillations.

 

Now with the advent (in time) pulses at point A (Fig. 2) will be switched to the flash lamp ЕL1. Integrated in the body of beacon, this design will allow you to apply further, if the beacon is out of order.

 

Unfortunately, the resource of flash units from portable camera is limited and unlikely to exceed 50 hours of operation in a pulsed mode.

 

 

Led Board installed in a regular case of beacon

 

A. KASHKAROV, St. P etersburg