voltage multiplier problem hi i ve just built a valve preamp and use a diode capacitor voltage multiplier to step the vac supply voltage up to approx vdv as the load resistance increases the rc constant decreases and hence the output voltage drops i need as high an output voltage as possible about v the circuit consists of seven voltage multiplier stages ie diodes and capacitors each capacitor develops about v across them and i take the output from across seven capacitors v each capacitor is mfd at v if i increase each of the capacitors rating mfd that will increase the rc constant and hence alleviate some of the problem these capacitors are going to be a little expensive as i need of them so what would happen if i connected a mfd at v capacitor in parallel with the output and hence in parallel with the seven mfd capacitors will it as i assume increase the c in circuit and hence increase the rc time constant if it does and my output voltage becomes more stable by doing this then i will have killed two birds with one stone as i am experiencing some hz ripple and hence amp hum and this new capacitor will smooth this out and can anyone recomend a suitable value for an inductor choke to be placed in the output line of the power supply to filter out the hz mains hum lowest resistance possible i ve not got my preamp with me at the moment because it is too much of a distraction i m at university and i ve got to get my dissertation finished in two weeks hence i m mailing not playing with my solderoing iron it ll be cheaper too in the long run especially if new large capacitors don t work as planned email please can t always read the net thanks in advance chris name mr chris smith twang on that ole guitar addrs scst uk ac liv csc uni liverpool university quest to build more and more hardware dgree computer science what ever the sun may be it is certainly not a ball of flaming gas d h lawrence all views expressed are my own and reflect that of private thought
