I have a 24 Volt Battery Charger, used for walk-behind forklifts. Its design consists of - transformer, capacitor (15uf), relay, diodes (x2), Ammeter (30A), and electronic circuit boards. I wish to place a manual radial timer in the circuit (8 hr MAX). Am I correct in assuming that the relay and circuit boards can be replaced by the manual timer? Why is the Cap copnnected to the transformer in the circuit? With the secondary transformer winding leads they run to the diodes (connected in parallel), Why?; off the diodes only the Positive (+) has a lead that runs to the output (also runs to the circuit board). The negative (-), come from the circuit board to the ammeter, then to the output. I dont understand how a negative is obtained, if not from the diodes. I have searched the net for explanations, and are yet to find any sites. I would like very much to gain an understanding of the whole battery charger concept. Thank you in advance.