This is a simple step up converter circuit which can increase input voltage of 3-12 volts into 4.5-22 volts at current 1-300 mA. It use small audio amplifier IC as main and use principle doubler voltage 2 times with diode and capacitor only without coil or transformer. So this circuit is easy and cheap. I like them.
How does it work.
“DC to DC Step up converter” is one other the switching regulator, transform low voltage into high voltage by raise level the voltage output is 2 times. of input voltage.
They suitable for low voltage power supply. For example: Rechargeable battery of radio communication, car battery, others small size battery etc.
Which is voltage between 3-12 volts convert voltage to output about 4.5-22 volts. The Block diagram how to use DC to DC converter ability to supply to a circuit or Other electronic appliances Which can not meet the power supply requirements.
Figure 1 Block diagram how to use DC to DC converter.
The simple principle of this circuit
As Figure 2 is perfectly simple DC to DC step up converter circuit of this project.
This circuit have the audio amplifier IC1-TDA2822 which We usually always use a small amplifier extends up to 2 watts. But this circuit is set as the astable multivibrator pulse generator to control on-off four diode switching (D1-D4) to transmission to charge and discharge at C10 to output. We will have voltage is nearly two times of input voltage, or as voltage drop across C10 with the input voltage there.
How to builds
This project use may use universal PCB or normal PCB as Figure 4 and assemble all parts on PCB as Figure 5 is components layout.
The components list.
Resistor 0.25 watts
R1,R2_____22K_____________= 2 pcs.
R3,R4_____4.7 ohms________= 2 pcs.
C1,C2,C3,C4__0.022uF 63V polyester ___= 4 pcs.
C5___________0.047uF 63V polyester____= 1 pcs.
C6,C7,C11__0.1uF 63V polyester____= 1 pcs.
C8,C9_____470uF 25V Electrolyte__ = 2 pcs.
C10_____1000uF 16V______”_______ = 1 pcs.
C11_____1000uF 50V______”_______ = 1 pcs.
D1-D4___MBR150____fast frequency Diode_________ = 1 pcs.
IC1____TDA2822 stereo audio amplifier 1 watts+ 1 watts________ = 1 pcs.
Terminal, Sockets 8 dip,PCB, and other.
Testing and Application.
We must to check this circuit for error.
Then to try a power supply to input point by voltage of 3-12 volts since it can use voltage in this range. Which at output will must be 2 times of input.
This project apply maximum current load of 300mA. And in while no load will pull current 6-8mA only. Application may use any battery between voltage of 3-12V to input of project. Then output is connected to any circuits that use voltage 4.5-22 volts and current about 300 mA.
I have a supper bright LED lamp that use 12 volts 1.5 watts only or 150mA but I have 6 volts battery only. As Video below. We cannot use them. Then I test it with this project. It cause voltage output is 11.8 volts. And I connect the LED lamp to output making it glow and have voltage 10.9 volts.
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