555 DC Voltage Doubler Circuit

This dc voltage doubler circuit produces a voltage that is twice its voltage supply. This is useful when a higher voltage level is needed out of a single lower voltage power supply. Since the current consumption levels are low in such cases, the circuit can be built with minimal resources.

Voltage Doubler Circuit Schematic

The electronic circuit is basically a square wave generator using the common LM555 timer IC. It is followed by a final stage made of transistors T1 and T2. The actual doubler circuit is made of D1, D2, C4 and C5 components.

The 555 dc voltage doubler timer IC works as an astable multivibrator and generates a frequency of about 8.5 kHz. The quare wave output drives the final stage made of T1 and T2. This is how the doubler works: by a low amplitude of the signal, transistor T1 blocks while T2 conducts. The minus electrode of the capacitor C4 is grounded and charges through D1. By a high amplitude of the signal, transistor T1 conducts while T2 blocks. However, capacitor C4 cannot discharge because it is blocked by D1. The following capacitor C5 is therefore charged with a combined voltage from C4 and the power supply (12V input).

On standby, the circuit delivers around 20 volts. The maximum load must not exceed 70 mA. The actual output voltage is around 18 volts giving an efficiency rating of 32 %.
On lower current ratings, the voltage is higher.
If a stable voltage lever is desired, a 3 pin voltage regulator IC can be added at the output. The regulator IC’s own current consumption must be added to the total current consumption which must not exceed 70 mA.

Diputado Johnson built a modified version of this circuit and posted some pictures on his website mobotgeek.blogspot.com. Here are some of them:

For more voltage doublers check the related posts bellow.

• gopal

Can we use voltage doubler circuit as input to 12v invertor?
If not then what can we do for it?

• nishant

How can i get 20 volt 10 ampere output from this circuit???

• himavanth

Hello sir , please give me details regarding the above circuit sir I want to increase my voltage without decrease in current I want to give input as 12volts 5amps and I need the volatge double or else upto 18volts but there should not be any decrease in the current. Please help me out sir.

• annalarasu

sir
the circuit is fine. i tried . when i give in put voltage of 5 volt dc it will not working. what can i do for it pl replay to my email. basically i am teacher in primary school. we r doing a project using windmill to charge the battery.

• suchita

this circuit is good but what is its frequency range?

• kunal senjariya

dear sir,

can you provide me voltage doubler circuit diagram for 3v 60ma current.

The actual output voltage is closer to the theoretical output voltage is greater if the 1N4001 diode is replaced with 1N5818. This is due to the reason that the 1N5818 has a lesser threshold voltage than that of the 1N4001 diode which is 1V.

A very nice circuit. Just the right circuit for my motorcycle supply problem.

My motorcycle electrical system can only output a maximum of 6V DC as it is an old Honda EX3 Malaysia MC. I wanted to install an LED strip as aesthetic lighting but it can only operate at 12v DC.

Built a modified version of it as the NPN and PND transistor shown are not available here in my place and as well as the two 1N4002 rectifier diodes witn 1N4001s.

Modified the 555 IC Based Generator Circuit from the basic Astable to the Astable with Diode so as make the Duty Cycle a perfect 50% (theoretically). R1 and R2 ar both 840Ohms and C1 to 0.1uF.

Replaced the NPN transistor with 2N3904 while the PNP with 2N3906.

The rest are of the same values.

THIS CIRCUIT WORKS!!!!

Found a similar description of this circuit at en.wikipedia.org under the name of “Diskson Multiplier” or “Dickson Charge Pump”.

With this circuit my motorcycle could now operate a low ampere rating 12V device without having to modify its electrical system completely.

• Simon John

Please I want to to do this particular circuit for my mini project, any chance u could give me a help?

By the way sir, should I send you the pics via an alternate email or through this site?

Hi 🙂

I would be glad to. Please allow me a day to take the pictures of it . I’ll upload the pictures the moment I have them.

Thank you…

• Popescu Marian

Can you send me some pictures of it? I want to publish them in this article and thank you for building this converter.

• Mihai

Rezistorul R1(100Ω) este prea mic. E inadmisibil la LM555 ca rezistorul R1 să fie mai mic de 1KΩ. Este evident că pentru a obţine la ieşie(3) semnal cu factor de umplere(duty cycle) 0,5 e necersar ca R1 să fie ZERO, lucru imposibil. Tranzistorul de descărcare (pin 7) are limitare internă de curent dar nu şi de putere disipată. În schema de faţă prin pinul 7 se închide la masă(GND) un curent de aproape 120mA(dacă R1=100Ω), cu mult peste ceea ce poate tranz. de descărcare(pin3). Pentru obţinerea factorului de umplere de 0,5(practic 0,1…0,9) se poate face încărcarea şi descăcarea cond. C1 separat, cu două diode fără a stresa tranz. de descărcare. Vezi şi “AN170_NE555 and NE556 applications” (pdf).

• Jim Keith

C3 is an input 12V noise filter. It is non-critical and can be almost any value.

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