Deyarî Multiplier

Zêdekirin, ew çavkên şîtên capacitor (çavka rectifier) ye ku bi vî re DC output voltage dihêne ku ji dawiyek ji bo tevî peak input AC dujiyê an zêdetir bibe. Li ser paragrafê, dikarin li ser full-wave voltage doubler, half-wave voltage doubler, voltage tripler û finally quadrupler bibin.

Half Wave Voltage Doubler

Forma wave input, diagrama circuit û forma wave output di figure 1 de nîşan dida. Li vir, her demê di cycle positive de, diode D1 dihêne conduct bikin û diode D2 di off condition da. Di vaxtenda, capacitor (C1) charges to VSmax (peak 2o voltage). Her demê di negative half cycle de, diode D2 dihêne conduct bikin û D1 diode di off condition da. Di vaxtenda C2 dihêne charge bikin.

Di next positive half cycle de, D2 di reversed biased condition (open circuited) da. Di vaxtenda C2 capacitor dihêne discharge bikin ji load û bi vî re voltage across this capacitor drops.

Lê, heta ku nayiye load across this capacitor, her du capacitor di charged condition de ne. Yani C1 charged to VSmax û C2 charged to 2VSmax. Di negative half cycle de C2 dihêne charged bikin yê (2VSmax). Di next half cycle de, half wave filtered by means of capacitor filter obtained across the capacitor C2. Here, ripple frequency same as the signal frequency. The DC output voltage of the order of 3kV can be obtained from this circuit.

Full Wave Voltage Doubler

Input waveform of full-wave voltage doubler is shown below.

Diagrama circuit û formay wave output nîşan dida di figure 3 de. Li vir; her demê di positive cycle de, diode D1 di forward biased condition de û capacitor C1 dihêne charged bikin to VSmax(peak voltage). At this time, D2 di reverse biased condition de. Her demê di negative cycle de, D2diode di forward biased condition de û capacitor C2 charged bikin. If the load is not connected across the output terminals, the total voltages of both the capacitorsare obtained as the output voltage. If some load is connected across the output terminals, then output voltage.

We can see that, both the half-wave and full-wave voltage doubler will give 2VS MAX as output. It does not require any centre-tapped transformer. The peak inverse voltage rating of diodes will be equal to 2VS MAX. When compared to half wave voltage doubler, the full-wave voltage doubler can simply filter high frequency ripples and output ripple frequency will be equal to twice the supply frequency. But the problem in full-wave voltage doubler is that; in between the input and output, the common ground is absent.

Voltage Tripler and Quadrupler

Using the method of extension of half-wave voltage doubler circuit, any voltage multipliers (Tripler, Quadrupler etc) can be created. When both the capacitor leakage and load are small, we can achieve tremendously high DC voltages by means of these circuits that include several sections to step-up (increase) the DC voltage.

Here; all through the first positive and negative half cycle is same as that of half-wave voltage doubler. Throughout the next positive half cycle, D1 and D3 conducts and C3 charges to 2VSmax. Throughout the next negative half cycle, D2 and D4 conducts and C4 charges to 2VSmax. When more diodes and capacitors are added, every capacitor will get charged to 2VSmax. At the output; odd multiples of VSmax can be attained, if measured from the top of transformer 2