| ??? 03/19/06 02:31 Read: times |
#112481 - Reed switch problems Responding to: ???'s previous message |
Suresh said:
Also, for once, i just connected the lamp directly to the 12 V through the reed switch (switch is driven by a driver circuit for ON / OFF operation). i could see only the switch getting closed parmanently. 'NO SWITCHING TOOK PLACE'(note: i just saw how the switch reacts, though the low rating was pointed out in the discussion previously..) and i found the contact opens only when the switch is taken out of the coil (in which the switch would be kept to drive the lamp) and when examined the switch seems to be in good condition.. Many years ago I had a similar problem when I tried to use a small reed switch to turn on & off a small tape player motor. Once switched on I lost control of the reed switch. The motor continued to run even though I had disconnected the coil from the circuit. Only when I interrupted the power in the motor circuit did the reed open. Right or wrong, I figured that since the reed is a magnetic material I guessed that the current flowing through the reed switch was generating enough of a magnetic field that held the reed closed, making it act like a SCR. I replaced the reed switch with a more traditional relay (Potter & Brumfield) and the circuit worked as expected. Hal |
