Battery powered Night Lamp Circuit Diagram

Ultra-low current drawing 1.5V battery supply

This circuit is usable as a Night Lamp when a wall mains socket is not available to plug-in an ever running small neon lamp device. In order to ensure minimum battery consumption, one 1.5V cell is used, and a simple voltage doubler drives a pulsating ultra-bright LED: current drawing is less than 500µA.
An optional Photo resistor will switch-off the circuit in daylight or when room lamps illuminate, allowing further current economy.

This device will run for about 3 months continuously on an ordinary AA sized cell or for around 6 months on an alkaline type cell but, adding the Photo resistor circuitry, running time will be doubled or, very likely, triplicated.

Circuit diagram :

Battery-powered Night Lamp Circuit diagram

Parts:

R1,R2___________1M 1/4W Resistors
R3_____________47K 1/4W Resistor (optional: see Notes)
R4____________Photo resistor (any type, optional: see Notes)

C1____________100nF 63V Polyester Capacitor
C2____________220µF 25V Electrolytic Capacitor

D1______________LED Red 10mm. Ultra-bright (see Notes)
D2___________1N5819 40V 1A Schottky-barrier Diode (see Notes)

IC1____________7555 or TS555CN CMos Timer IC

B1_____________1.5V Battery (AA or AAA cell etc.)

Circuit operation:

IC1 generates a square wave at about 4Hz frequency. C2 & D2 form a voltage doubler, necessary to raise the battery voltage to a peak value able to drive the LED.

Notes:

IC1 must be a CMos type: only these devices can safely operate at 1.5V supply or less.
If you are not needing Photo resistor operation, omit R3 & R4 and connect pin 4 of IC1 to positive supply.
Ordinary LEDs can be used, but light intensity will be poor.
An ordinary 1N4148 type diode can be used instead of the 1N5819 Schottky-barrier type diode, but LED intensity will be reduced due to the higher voltage drop.
Any Schottky-barrier type diode can be used in place of the 1N5819, e.g. the BAT46, rated @ 100V 150mA.

Streamcircuits

Comments

Digital Fan Regulator Circuit Diagram

This is the project of Digital Fan Regulator Circuit diagram. The circuit presented here can be used to control the speed of fans using induction motor. The speed control is nonlinear, i.e. in steps. The current step number is displayed on a 7-segment display. Speed can be varied over a wide range because the circuit can alter the voltage applied to the fan motor from 130V to 230V RMS in a maximum of seven steps. The triac used in the final stage is fired at different angles to get different voltage outputs by applying short-dura-tion current pulses at its gate. For this pur-pose a UJT relax-ation oscillator is used that outputs sawtooth waveform. This waveform is coupled to the gate of the triac through an optocoupler (MOC3011) that has a triac driver output stage. Pedestal voltage control is used for varying the firing angle of the triac. The power supply for the relaxation oscillator is derived from the rectified mains via 10-kilo-ohm, 10W series dropping/limit-ing...

Home automation with Telegram BOT

The project I’m going to describe today it’s a sort of proof of concept that will demonstrate the possibility to remote control sensors and actuators (for example a couple of relays) via Telegram. Telegram is an instant messaging application, similar to the famous Whatsapp. Last June, the Telegram developers announced that a new set of APIs were available to develop bots. [ ]

24 Hour Timer

Description: These two circuits are multi-range timers offering periods of up to 24 hours and beyond. Both are essentially the same. The main difference is that when the time runs out, Version 1 energizes the relay and Version 2 de-energizes it. The first uses less power while the timer is running; and the second uses less power after the timer stops. Pick the one that best suits your application. Notes: The Cmos 4060 is a 14 bit binary counter with a built in oscillator. The oscillator consists of the two inverters connected to Pins 9, 10 & 11; and its frequency is set by R3, R4 & C3.The green Led flashes while the oscillator is running: and the IC counts the number of oscillations. Although it's a 14 bit counter, not all of the bits are accessible. Those that can be reached are shown on the drawing. By adjusting the frequency of the oscillator you can set the length of time it takes for any given output to go high. This output then switches the transistor; which in turn o...

ffd

Search This Blog