A 12V to 24V DC-DC converter is an important part of today’s electronics. They are generally used for industrial purposes such as load matching for variable drives & also for the testing/troubleshooting of small-scale electronics. So, in this project, we are going to build a simple 12V to 24V DC-DC Converter circuit using NE555 Precision timer IC & a 24V/1W Zener Diode IC.
A NE555 timer IC serves as the core of this circuit. The IC possesses an oscillation frequency ranging from 670 to 680 Hz. Here, this NE555 timer acts as an astable multivibrator An astable multivibrator is a free-running oscillator that switches continuously between its two unstable states. With no external signal applied, the transistors alternately switch from cutoff to saturation state at a frequency that RC time constants of the coupling circuit determine. If these time constants are equal (R and C are equal) then a square wave will generate with a frequency of 1/1.4 RxC. Hence, an astable multivibrator is also a pulse generator or a square wave generator.
Hardware Required
The following components are required to make the DC-DC Converter Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | IC | NE555 Timer | 1 |
| 2. | Transistor | BD139 | 1 |
| 3 | Resistors | 1K, 10K | 1 |
| 4. | Zener Diode | 24V/1W | 1 |
| 5. | Schottky Diode | 1N5819 | 1 |
| 6. | Ceramic Capacitors | 10nF, 560pF | 1 |
| 7. | Electrolytic Capacitors | 1uF/50V | 1 |
| 8. | Breadboard | – | 1 |
| 9. | Battery | 12V | 1 |
| 10. | Inductor | 100uH | 1 |
BD139 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of BD139
NE555 IC Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer
DC-DC Converter Circuit
Working Explanation
This circuit revolves around the functioning of a NE555 Timer IC in Astable Mode. certain frequency pulses are generated with the 555 timer IC by using 1K, 10K, and 560pF capacitors. Pin 6 and 2 of the IC are connected with each other, making the IC self trigger continuously, providing pulses at the output pin 3.
A BD139 transistor is connected to the output of the IC. When each pulse is received the transistor becomes ON and generates a certain amount of energy in the 100uH inductor and when the transistor is turned OFF the saved energy of the inductor is fed to the 1uF capacitor through the 1N5819 Schottky diode. The output current of the circuit is 100mA to 150mA.
Applications
- Common use in applications such as test bench supply, trainer board supply, etc.
