| ??? 12/10/07 00:20 Read: times |
#148017 - It is dead easy but ... Responding to: ???'s previous message |
That is if You have the room for the big capacitors and can live with the heat from the resistors.
Let's assume that the solenoid needs a 36 volt pulse to pull for sure and that it keeps it's grip with only 12 volts and that it has a 100 ohm resistance. I would try with nothing less that 2000uF capacitor with 40 volt rating. Those tend to be big. The size of the capacitor depends on the moving mass and the lenght of the movement of the solenoid. The bigger mass and movement the bigger capacitor You need. The resistor we need here would be 200 ohms rated at 4 watts and it would still be quite warm (2.8 watts of dissipation). Then we have the charging trouble. If the solenoid has to be acting many times in succession (rattling) it would not work. There has to be a dead time after switching the thing off to let the capacitor to charge for a new pull. Rattling can be used to clean the contacts for example (another typical MCU job). |
| Topic | Author | Date |
| Looking for a one of six selector chip | 01/01/70 00:00 | |
| HMM | 01/01/70 00:00 | |
| sounds like you need a PAL | 01/01/70 00:00 | |
| have you looked at 74HC237 with a 1 Hz clock? | 01/01/70 00:00 | |
| Oh-Oh-Use-Mcu | 01/01/70 00:00 | |
| Driving is easy. | 01/01/70 00:00 | |
| It is dead easy but ... | 01/01/70 00:00 | |
| Current, not voltage | 01/01/70 00:00 | |
| Practise and Theory | 01/01/70 00:00 | |
| I decided to settle for the MCU | 01/01/70 00:00 | |
| Memory relays and reset problems | 01/01/70 00:00 | |
| So ... you\'re using a latching relay? | 01/01/70 00:00 | |
| Example of a solenoid driver | 01/01/70 00:00 | |
| chip driver | 01/01/70 00:00 | |
| Yes, that's the kind of thing | 01/01/70 00:00 | |
| No, voltage, not current! | 01/01/70 00:00 | |
| AC solenoids | 01/01/70 00:00 | |
| Thread morphing... | 01/01/70 00:00 | |
PLC | 01/01/70 00:00 | |
| trivial, maybe, but why not use a 'trivial' uC | 01/01/70 00:00 | |
| Trivial microcontrollers | 01/01/70 00:00 |