Showing posts with label Lamp. Show all posts
Showing posts with label Lamp. Show all posts
Thursday, March 24, 2011
Mosfet Dimmer Circuit for Halogen lamp
A light dimmer circuit is a means of controlling the "brightness" level of a lamp, in this circuit we will use a 555 timer to control the brightness level of a low voltage incandescent bulb of up to 60 watts.
Mosfet Dimmer Circuit for Halogen lampThe circuit works by pulse-width modulating the 12V supply to the lamp. The 555 timer is configured as a "variable cycle", astable oscillator running some where around 300 Hz.
Potentiometer 47K from minimum to maximum varies the values accordingly the duty cycle of the 555 timer controlling light dimmer circuit.
The power mosfet used here would be a TO-220 type such as MTP3055E or similar. Note the need for a TO-220 type heat sink for full rated loads.
Potentiometer 47K from minimum to maximum varies the values accordingly the duty cycle of the 555 timer controlling light dimmer circuit.
The power mosfet used here would be a TO-220 type such as MTP3055E or similar. Note the need for a TO-220 type heat sink for full rated loads.
Saturday, March 5, 2011
Touch Activated 12V Lamp Circuit Using Transistor
This circuit uses three bipolar transistors to accomplish the Same result (previous post) with the touch contact referenced to the negative or ground end of the supply. The 12volt 20W lamp will be turn on when the contacts are touched with skin resistance about 2M or less. This circuits are available also for other applications, for additional current the lamp could be replace with a 12V relay and diode across the coil.
Since the base of a bipolar transistor draws current and the current gain is usually Less than 200, three transistors are needed to raise the microamp current levels through the touch contacts to a couple amps needed by the light.
Touch Activated Light circuit using Mosfet IRF510
Here is a circuits light a 12V/20 watt lamp when the contacts are touched and the skin resistance is about 2 Megs or less. This circuit uses a power MOSFET (IRF510) which turns on when the voltage between the source and gate is around 6 volts. The gate of the MOSFET draws no current so the voltage on the gate will be half the supply voltage or 6 volts when the resistance across the touch contacts is equal to the fixed resistance (2 Megs) between the source and gate.
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| Touch Activated Light circuit using Mosfet IRF510 |
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| Mosfet IRF510 Pi |
Drain to Source Voltage : 100 V
Drain to Gate Voltage : 100 V
Continuous Drain Current (ID) : 5.6 A
Pulsed Drain Current (IDM) : 20 A
Gate to Source Voltage (VGS) : ±20 V
Maximum Power Dissipation (PD) : 43 W
NE555 Lamp Dimmer Circuit
Here is a 12 volt lamp dimmer circuit that can be used to dim a standard 25 watt automobile brake or backup bulb by controlling the duty cycle of a astable 555 timer oscillator.
[read here...]
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| NE555 Lamp Dimmer Circuit |
When the wiper of the potentiometer is at the uppermost position, the capacitor will charge quickly through both 1K resistors and the diode, producing a short positive interval and long negative interval which dims the lamp to near darkness. When the potentiometer wiper is at the lowermost position, the capacitor will charge through both 1K resistors and the 50K potentiometer and discharge through the lower 1K resistor, producing a long positive interval and short negative interval which brightens the lamp to near full intensity. The duty cycle of the 200 Hz square wave can be varied from approximately 5% to 95%. The two circuits below illustrate connecting the lamp to either the positive or negative side of the supply.
Saturday, February 26, 2011
IRF530 Fet Flasher Circuit
This is a simple fet flasher circuit that can be used for flashing 12V lamps especially that is used on automobiles.The flasher circuit is based on transistor BC557 and MOSFET IRF530 where the Q2 provides the necessary drive for the lamp.Any number of bulbs can be flashed using this circuit provided that the total load must not exceed 42 Watts. Circuit of this kind are particularly suited for road, traffic and yard alerts and in all cases where mains supply is not available but a powerful flashing light is yet necessary
Flashing frequency can be varied within a limited range by changing C1 value.
List Componet
R1 : 6K8 R2 : 220K R3 : 22K C1 : 100µF/25V C2 : 10µF/25V D1 : 1N4002 Q1 : BC557 Q2 : IRF530 LP1: 12V/21W Car Filament Bulb SW1: SPST Switch (3 Amp minimum)
Sunday, February 20, 2011
NE555 12VDC Fluorescent Lamp Driver Circuit
This is a circuit of 12VDC fluorescent lamp Driver for those who look for Fluorescent lamp driver using ordinary transformers. The transformer used is a step-down transformers from 120 to 6V in reverse, so that with primary voltage 12V could produce 350V for output. This voltage is used to turn on the fluorescent lamp without heating the filament.
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| NE555 12VDC Fluorescent Lamp Driver Circuit |
The IC1 TLC 555 is wired as an astable multivibrator for producing the necessary oscillations.The MOSFET Q1 is used to amplify the oscillations produced by the IC1.The out put of MOSFET is connected to the primary of the step up transformer to produce a ~350 V AC for driving the florescent lamp.
Note:
- Take note that heat sink should be used on Q1, and be careful of the electric shock from the output voltage!
- For T1, use a 10W ,230V to10V step down transformer in the inverted configuration.That is 10V winding must be connected to the MOSFET side and 240V winding must be connected to florescent lamp side.
C1 : 100uF/25V
C2,C3 : 0.01/25V Ceramic Capacitor
C4 : 0.01/1kV Ceramic Capacitor
R1 : 1K
R2 : 2.7K
Q1 : IRF510 MOSFET
U1 : NE555 Timer IC
T1 : see note
LAMP : 4W Fluorescent Lamp
Saturday, February 12, 2011
12 VDC Fluorescent Lamp Inverter
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| 12 VDC 8 Watt Fluorescent Lamp Inverter Circuit |
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| Transformer details |
The circuit shown in the above has been Designed to drive an 8Wfluorescent lamp from a 12V source, using an Inexpensive inverter based on the ZTX652 transistor. The inverter will from operate from supplies in the range of 10V to 16.5V, attaining efficiencies up to 78% thus making it Suitable for use in on-charge systems Such as caravans / mobile homes / RVS as well as periodically charged systems Such as roadside lamps, camping lights or lights etc outhouse. Other features of the inverter are That it oscillates at an inaudible 20kHz and That it includes reverse polarity protection.
For more detail diodes.com
Wednesday, February 9, 2011
220 Volts Flashing Lamps
This circuit is intended as a reliable replacement to thermally-activated switches used for Christmas tree lamp-flashing.
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| 220 Volts Flashing Lamps Circuit |
The schematic diagram formed by Q1, Q2 and related resistors triggers the SCR. Timing is provided by R1, R2 & C1. To change flashing frequency do not modify R1 and R2 values: set C1 value from 100 to 2200µF instead. Best performances are obtained with C1= 470 or 1000µF and R4= 12K or 10K. Due to low consumption of normal 10 or 20 lamp series-loops intended for Christmas trees (60mA @ 230V typical for a 20 lamp series-loop), very small and cheap SCR devices can be used, e.g. C106D1 (400V 3.2A) or TICP106D (400V 2A), this last and the suggested P0102D devices having TO92 cases.
List Component of 220 Volts Flashing Lamps circuit
R1 : 100K
R2,R5 : 1K
R3,R6 : 470R
R4 : 12K
C1 : 1000µF/25V
D1-D4 : 1N4007
D5 : P0102D
Q1 : BC327
Q2 : BC337
PL1 : Male Mains plug
SK1 : Female Mains socket
Warning! The device is connected to 220Vac mains, then some parts in the circuit board are subjected to lethal potential! Avoid touching the circuit when plugged and enclose it in a plastic box.
Wednesday, February 2, 2011
Simple Lamp Dimmer 220V using Triac
A very simple dimmer circuit with only the essentials. (In this circuit, the values are given for a BT138 at 220V AC, for 115V AC you may have to experiment with the values.)
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| Simple lamp Dimmer 220V Circuit |
- D1 = diac (silicon bidirectional trigger device) BR100, ER900 or similar
- Tr1 = triac BT138, TIC226...
- This circuit is potentially dangerous! this is nothing for beginners!
R1 can vary from one triac to another, put a 220KΩ trimmer in its place and adjust. After adjustment, measure the result and replace the trimmer with an ordinary resistor of the same value.
Circuit From: http://home.scarlet.be/
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