This Simple Led Driver Circuit using IC LT1932 chip works like special power for LED lights.
LEDs do not like too much or too little power so this circuit gives just a right amount and then LED shine good and live long.
LT1932 chip work like traffic police it controls power flow nice and smooth so LED light up perfect.
Circuit Working:
Parts List:
| Category | Component | Quantity |
|---|---|---|
| Resistor | 1.5k 1/4 watt | 1 |
| Capacitors | Electrolytic 1µF 25V | 2 |
| Semiconductors | IC LT1932 | 1 |
| Schottky diode MBR0540 | 1 | |
| LEDs White 5mm 20mA | 3 | |
| Coil Inductor 4.7uH | 1 | |
| ON/OFF Switch | 1 |
This light run on two small AA battery like pen cell, rechargeable type.
No example in this design so we can make it how we like it is used for searchlight, cupboard light, on road or for checking things and many ideas possible!
Main part is small IC chip LT1932 is only 6 pin SMD type from company called Linear Tech.
This chip is special type and it boost low voltage and give steady current it is very good for LED because LED need correct current not just voltage.
LT1932 keep LED current perfect even when battery gives more voltage than LED need so it is good for battery powered designs.
One resistor outside chip control how much current goes to LED so that we can choose between 5mA to 40mA.
In this circuit we can set it to 15mA using 1.5k ohm resistor R1.
Chip IC1 connects to two batteries and powers three white LEDs D2, D3, D4 and this design follow LT1932 datasheet rules exactly.
Use small SMD board to make this circuit.
But be careful since this is switching type circuit the design of board is very important.
Wrong design can cause noise and signal problem.
Be sure wire path around pin 1 should be short and neat.
Also use ground plane under chip to reduce noise.
Pin 1, diode D1 and capacitor C2 must be close together as they switch very fast in nanoseconds so keep a track short.
Resistor R1 ground must go only to pin 2 and do not share it with other parts as this will keep signal clean.
Use good quality capacitor like ow ESR for C2 to reduce ripple.
Also D1 must be fast Schottky diode with low voltage drop which must handle more voltage than LED.
MBR0540 500mA, 40V is good choice.
Inductor L1 also is very important it uses ferrite core not iron because it loses less power at 1.2MHz.
Use 4.7 microhenry coil that can handle at least 500mA current.
Note: If we want only one LED at output and just connect LED anode to D1 cathode and cathode to pin 3 of the chip.
How to Build:
To build a below mentioned Simple Led Driver Circuit using IC LT1932 follow these steps:
Get All Parts Ready:
- Collect all parts we need for this circuit as mentioned in the circuit diagram.
- Be sure they are good and match what circuit need.
Make the Layout:
- Use SMD board and put parts same like in circuit diagram.
- Place LT1932 chip and other parts in correct place on board.
Solder the Parts:
- Now solder each part one by one.
- Be careful with part direction like polarity and do not make mistake.
- Use small tip solder iron for clean and easy work.
Connect Battery:
- Take two AA size rechargeable pen cells and connect it to circuit.
- Watch plus and minus carefully and wrong side can damage parts.
Try the Circuit:
- After building in one done, test the circuit.
- See if LEDs turn ON and check if current is correct.
Final Check:
- After we put circuit inside box or case do last test.
- If something is wrong then fix it before we use the light.
Note:
- This is just the basic steps.
- Always look at component datasheets and be safe while working with electronics.
Conclusion:
Simple Led Driver Circuit using IC LT1932 chip is good and efficient for powering LEDs in many uses.
It work like constant current source so LED stay with same brightness even if battery voltage goes up or down.
If we make circuit in a proper way and use good parts then this LED driver with LT1932 can give strong and steady light. This circuit is good for small portable things or low power projects.