This circuit is like a tiny supercharger for your batteries.
It can take a weak 1.5V battery, like the kind you find in AA batteries, and increase the voltage to a more usable 5V.
This is especially helpful for powering small electronic devices that need 5V to work properly.
The MAX756 chip is like a tiny superhero that helps the circuit efficiently convert the voltage
Circuit Working:
Parts List:
| Category | Component | Quantity | Notes |
|---|---|---|---|
| Resistor | 470Ω | 1 | |
| Capacitors | Ceramic 100nF | 1 | |
| Electrolytic 100µF 16V | 2 | ||
| Semiconductors | IC MAX756 | 1 | |
| Diode 1N5817 | 1 | ||
| LEDs | Red 5mm 20mA | 1 | |
| Coil Inductor | 22uH | 1 | |
| Miscellaneous | ON/OFF Switch | 1 | |
| Power Source | Battery 1.5V | 1 |
Here is an intriguing circuit for producing a stable and reliable 5V DC output up to 200mA from a standard 1.5V AA sized cell.
At the core of this design is the MAX756 IC from Maxim, which serves as a CMOS step up DC to DC switching regulator tailored for small low input voltage or battery powered setups.
The MAX756 can handle a positive input voltage as low as 0.7V and convert it to a higher user selectable output voltage of 5V or 3.3V.
This IC boasts a typical full load efficiency exceeding 87%.
It integrates a switch mode regulator with an N channel MOSFET, a precision voltage reference and a power fail detector into a single monolithic device.
The MOSFET is of the ‘sense FET’ variety, chosen for optimal efficiency and features an extremely low gate threshold voltage to facilitate startup under low battery conditions typically 1.1V.
The circuit can be easily assembled on a compact rectangular PCB, with all connections kept as short as possible.
It is advisable to include a high quality 8 pin DIP socket for the IC if possible.
It is worth noting that the DC resistance of the power inductor L1 significantly impacts efficiency.
To achieve the highest efficiency the DC resistance of L1 should be limited to 0.03 ohms or less using a standard thru hole type power inductor.
Additionally, the equivalent series resistance ESR of all capacitors both bypass and filter affects the circuits efficiency.
Optimal performance is achieved by using specialized low ESR capacitors.
Formula:
Before we get into the formula, it is crucial to understand that although the MAX756 is capable of being utilized in boost converter designs, this is not its primary function, and it may not be the best option in every situation.
Vout = Vin / (1 – D/Dmax)
where:
- Vout is the output voltage
- Vin is the Input voltage
- D is the duty cycle (the proportion of the switching period that the switch is on)
- Dmax is the maximum duty cycle allowed by the IC
In essence, the formula says that the input voltage divided by a duty cycle related factor equals the output voltage.
The output voltage rises in proportion to the duty cycle.
But the maximum duty cycle that the IC permits Dmax sets a restriction on the maximum output voltage.
How to Build:
To build a Simple 1.5V to 5V Voltage Converter using IC MAX756 use the following steps mentioned below:
Prepare the PCB:
- Design or obtain a PCB layout for the circuit.
- Place all components on the PCB according to the circuit diagram.
Solder the components:
- Solder the IC socket if using and other components onto the PCB.
- Start with the smaller components and then move to larger ones.
Connect the components:
- Use thin, insulated wire to connect the components according to the circuit diagram.
- Keep the connections as short and direct as possible.
Install the IC:
- If you’re using the IC socket, insert the MAX756 IC into the socket.
- Make sure to align the notch on the IC with the notch on the socket.
Test the circuit:
- Insert a 1.5V AA cell into the battery holder.
- The LED should light up, indicating that the circuit is working and generating a stable 5V output.
Finalize the circuit:
- Once the circuit is working correctly secure all components and wires using hot glue or other adhesive to prevent them from moving or coming loose.
Note:
Remember to follow safety precautions when working with electronics such as wearing safety goggles and avoiding static electricity.
Conclusion:
To conclude, the MAX756 IC offers a simple and efficient solution for converting a low 1.5V input voltage to a stable 5V output, making it ideal for powering various electronic devices or circuits from a single AA battery or similar power source.
The circuit can be easily built with a few components and provides a reliable voltage conversion with good efficiency.