LDR Pole Light Switch Circuit
by Jim Keith in 555 | Lights | Tested |
My vintage (62 year old) pole light has always been controlled by a timer—a source of continual frustration due the requirement of readjustment for the ever-changing seasons. However, after knocking it over (I backed my car into it…), I decided it was time for an update. The circuit consists of a light dependent resistor (LDR), TLC555 (applied as Schmitt...
Light Activated Siren Circuit
by Jim Keith in Audio | Lights |
This light activated siren could make an unknowing “victim” wet his pants when turning on the lights in a dark room. This thing is LOUD! Power into the module is 3W and produces a 123db sound level from its 50mm diameter diaphragm. It wavers between 2kHZ and 4kHZ. An LDR senses ambient light level and switches on the power...
Light Activated Switch
by Sebastian Kushero in Lights |
The light activated switch circuit can be used for switching OFF a particular lamp or group of lamps in response to the varying ambient light levels. The unit once built can be used for switching OFF a lamp when dawn breaks and switching it ON when dusk sets in. The power supply is a standard transformer, bridge, capacitor network,...
Automatic Street Light Circuit
by Srihari Rao in Lights | Useful |
There have been lot of problems in street lights. Major problem in some places is every evening a person has to come and switch ON the street light and it should be again switched off in morning. Yes, this may not be the situation in everywhere but exists in many places. So this problem can be overcome by using...
LDR = Light Dependent Resistor = Photoresistor
by P. Marian in Theory |
You’re asking what is LDR? It stands for Light Dependent Resistor or Photoresistor, which is a passive electronic component, basically a resistor which has a resistance that varies depending of the light intensity. A photoresistor is made of a high resistance semiconductor that absorbs photons and based on the quantity and frequency of the absorbed photons the semiconductor material...
Light Alarm Circuit with LDR
by P. Marian in Alarms |
This musical light alarm circuit is very simple, uses only 7 components, a LDR and a 3.6 V battery or 3 x 1.2 volts rechargeable batteries. The well-known UM66 is used as the sound generator and will give a pleasent wake up alarm. As you probably know the LDR is a light dependent resistor. Normally the resistance of an...
LDR PC Desk Lamp
by T.K. Hareendran in Lights | Tested |
Most of the PC desk lamps available in the market light up whenever there is an input power. These don’t take into account whether there is a real need for the light or not. Here is an intelligent PC desk lamp circuit that overcome the problem. It senses the light level in the room to determine the actual need...
Christmas LED Lights Circuit
by D Mohankumar in Lights |
Using this simple Christmas LED lights decoration circuit, you can make an 18 LED flasher to decorate the Christmas Tree. The White, Blue and Red LEDs flash at different rates to give a colorful display. It is a light sensitive circuit so that it will turn on in the evening automatically and stays on till morning. The circuit uses...
Automatic Lawn Light with LDR
by T.K. Hareendran in Lights | Tested |
Circuit of a compact and true solid-state automatic lawn light is described here. The circuit can be used to switch on incandescent garden light bulbs at desk and switch off them at dawn. A 10 mm encapsulated light dependent resistor (LDR) here works as the twilight detector. The whole circuit can be housed in a very small plastic cabinet....
Day Charger circuit
by D Mohankumar in Power supply |
This LDR controlled Adjustable charger can be used to charge the Rechargeable battery of portable devices. It charges the battery only during day time. This saves energy and prevents overcharging of the battery. The output voltage from the charger varies from 6 – 12 volts which can be adjusted. Current flow depends on the ambient light in the room....