d.c. voltage doubler using a 4049

36 30 68 60 70 d.c. voltage doubler using a 4049 This simple circuit can produce a d.c. voltage which is approximately twice the supply voltage, in the no- load condition. The 4049 IC contains a total of six inverters. Two of them, Nl and N2, form an oscillator together with R1 and C3, of which the frequency is about 10 kHz. The remaining inverters, N3 ... N6, are connected in parallel and operate as a buffer stage to reduce the load- dependence of the circuit. Depending on the clock signal of the oscillator, point A in figure la is connected to the earth rail for a particular time per period and to the supply voltage for a particular time. Whilst point A is connected to earth, capacitors Cl and C2 charge up to the supply voltage via diodes Dl and D2. The oscillator then switches point A to the supply voltage potential during the remain- 5 27.5 —12.5 40 10 26.5 —11.5 75 15 25.5 —10.5 115 G. Ramm 52 68 44 Table. Supply voltage (V) 10 15 Jout Uout (V) (mA) Figure 1a 1b Ua.c, (...