What is a 555 timer light alarm activated circuit?
The main part of this light activated alarm circuit is 555 timer IC. It is mainly used in timing applications. It produces the oscillations required. This can be operated in three modes. These three modes are Monostable mode, Astable mode, Bistable mode.
What is a 555 timer in a circuit?
The 555 timer IC is an integrated circuit (chip) used in a variety of timer, delay, pulse generation, and oscillator applications. Derivatives provide two (556) or four (558) timing circuits in one package. It was commercialized in 1972 by Signetics.
Can you put a timer on solar lights?
Some solar-powered chicken coop lights come with timer functions which can be very useful for homeowners. You can use these timers to keep the light on for a certain amount of time, like 3 or 5 hours, depending on how much artificial daylight you’d like to provide.
What is a 555 timer used for?
The 555 timer IC is a very cheap, popular and useful precision timing device which can act as either a simple timer to generate single pulses or long time delays, or as a relaxation oscillator producing a string of stabilised waveforms of varying duty cycles from 50 to 100%.
What is a light sensor circuit?
The light sensor circuit is a simple electrical circuit, which can be used to control the (switch on and off) electrical load appliances like lights, fans, coolers, air conditioners, street lights, etc., automatically. Hence, we can describe it as an automatic light sensor.
What is LDR circuit?
Photoresistors, also known as light dependent resistors (LDR), are light sensitive devices most often used to indicate the presence or absence of light, or to measure the light intensity. LDRs have a sensitivity that varies with the wavelength of the light applied and are nonlinear devices.
Can a 555 timer be used for an intruder alarm?
This light activated relay circuit presented here uses the 555 timer IC and a light dependent resistor or LDR to form a light sensitive relay in an intruder alarm system or for switching on a lamp at Sun set and off at Sun rise.
How does a 555 timer drive a transistor?
The 555 timer drives the transistor at 222 kHz rate. The seven LED groups can be connected paralelly if their forward voltages match. If not, the LED group with the lowest forward voltage value will dim out the other group (s).
What kind of timer does an LED driver use?
The LED driver uses a CMOS 555 timer since it operated with low voltages and can work for about 190 hours when using a single NiMH battery cell rated at 2000 mAh. The 555 timer drives the transistor at 222 kHz rate. The seven LED groups can be connected paralelly if their forward voltages match.
How long can a solar garden light run?
The circuit can run these LEDs for as long as 10 hours on full brightness. A 6V 4AH or 4.5AH lead-acid battery is utilized here which will charge in the first part of the day and in the night, it will give the capacity to the 12 LEDs.