| ??? 04/10/06 12:48 Read: times |
#113964 - Charge pump Responding to: ???'s previous message |
Suresh said:
I need to stepup a 12V rectified o/p to 24 Vdc to drive a solenoid coil (rated 24VDC/4.5W) So, you need 24V at about 0.2A. If availability of parts and costs play a key role, then you can use the following cirucit:  Another advantage of this very simple circuit is, that it does not need any inductor! The TDA2003 is a 10W power amplifier chip for car radio applications coming in a TO220/5 package. It's connected to work as oscillator (about 4kHz) and to do charge pumping. The voltage drop across diodes will make that the output voltage will rise to only about 22.5V. But in this application this is of no harm, because any 24V relay will work at voltages greater 19V, some even already at 16V. But as Andy already mentioned, it's much better to use a mains transformer for the purpose, if you can. Kai |
| Topic | Author | Date |
| step up voltage regulator | 01/01/70 00:00 | |
| 12V rectified output? | 01/01/70 00:00 | |
| additional Transformer occupies space | 01/01/70 00:00 | |
| 18V Center Tap Transformer? | 01/01/70 00:00 | |
| size ? | 01/01/70 00:00 | |
| Mistake in analysis | 01/01/70 00:00 | |
| why two? | 01/01/70 00:00 | |
| Of course! | 01/01/70 00:00 | |
| easier | 01/01/70 00:00 | |
| You are righ Kai. I didnt analyse this w | 01/01/70 00:00 | |
| nope, that is why it is called a switche | 01/01/70 00:00 | |
| Step-up, step-down | 01/01/70 00:00 | |
| ON/OFF(active low) pin? | 01/01/70 00:00 | |
| Shutdown pin | 01/01/70 00:00 | |
Thanks. | 01/01/70 00:00 | |
| Try this simple circuit. It might work | 01/01/70 00:00 | |
| LM2577 | 01/01/70 00:00 | |
| expensive is relative | 01/01/70 00:00 | |
| Charge pump | 01/01/70 00:00 | |
| Thank you all | 01/01/70 00:00 | |
| Two are needed! | 01/01/70 00:00 |