Lighting | Electronic Project Circuits

Posts Tagged ‘Lighting’

Automatic Headlight Brightness Switch

Driving the highway with your high-beam headlights can really increase your visibility, but can he a blinding hazard for other drivers. This simple circuit can be wired into your headlight switch to provide automatic switching between high and low beam headlights when there is oncoming traffic. It does this by sensing the lights of that traffic. In this way, you can drive safely with your high-beams on without blinding other drivers.

Parts:
R1 5K 1/4W Resistor
R2, R3, R4 5K Pot
Q1 NPN Phototransistor
Q2 2N3906 PNP Transistor
K1 Low Current 12V SPST Relay
K2 High Current 12V SPDT Relay
S1 SPST Switch
B1 Car Battery
MISC Case, wire, board, knobs for pots

Notes:
1. Q1 should me mounted in such a way so it points toward the front of the car with a clear line of site. Suitable places are on the dashboard, in the front grill, etc.
2. Adjust all the pots for proper response by testing on a deserted road.
3. S1 enables and disables the circuit.
4. B1 is, obviously, in the car already.
5. Before you try to connect this circuit, get a wiring diagram for your car. Some auto manufacturers do weird things with wiring.
6. Connection A goes to the high beam circuit, B goes to the headlight switch common and C connects to the low beam circuit.

Be the first to comment - What do you think? Posted by admin - October 6, 2007 at 9:47 am

Categories: Automotive, Lighting Tags: Automotive, Light relay switch, light switch, Lighting

Dusk to dawn switch by IR-Diode

This dusk to dawn switch switches on the lamp at night and automatically switches off the lamp in daytime.
The circuit uses an old-fashioned relay as switching element which makes it suitable for all lamp types: not only
incandescent but also TL and compact fluorescent.

description

When it is light, infrared-diode D1 will be conducting; the voltage on the anode of D1 (see arrow) will be high.
A current will flow through R1 into the base of T1. Because T1 pulls down the base of T2 the relay is switched off.

In the dark, D1 will stop conducting; the voltage on the anode of D1 will become low.
Consequently the base current of T1 will decrease and current will flow into the base of T2 via R3: the relay is switched on.

-The light sensitivity can be adjusted wiith P1; lower resistance = more light necessary to switch off the relay.
-R2 creates some hysteresis to prevent fllickering at the circuit’s trip level.
-C1 creates a low pass filter with R1, allso to prevent flickering and to decrease sensitivity to 50Hz hum.
-The trip-voltage on the anode of D1 (seee arrow) is about 1 Volt; below 1V the relay will switch on; above it will switch off.
-I used a LED-shaped IR diode; very conveenient for waterproof mounting in the lamp fixture.
-The circuit will also work with other liight sensors as photo diodes/transistors and LDR’s. IR diodes have the advantage that
they are not very sensitive to light from TL or other fluorescent lamps which emit very little infrared !

Read More Source :http://www.geocities.com/tjacodesign/duskdawn/duskdawn.html
Thank you.

Be the first to comment - What do you think? Posted by admin - August 30, 2007 at 9:56 pm

Categories: Electronic Control Tags: infrared switch, IR remote control, Lighting

12V 6 Amp Solar Power Center (SPC2) by TL2272

The SPC2 is a solar power center, it can be used to handle all of the power functions for small 12 Volt solar powered devices. It contains a photovoltaic charge controller and a low voltage load disconnect circuit. The low voltage disconnect has a load on-off switch, and a battery low voltage indicator. By using the SPC2 as the center of a solar powered device, long battery life is assured. The SPC2 is primarily designed to be a solar lighting controller, it can be used to power radios and other high capacitance loads with a minor switch and circuit modification (shown in dotted lines on the schematic).
Read More Source : http://www.solorb.com/elect/solarcirc/ccntlvd/