does relays has positve &negetive pole

[mambo29]

if i am using a dc relay ..as a coil type relay..i was wondering does it has polarity? if a inject the wrong pole (if it have) will i spoil the coil? pls reply if anyone know....thanks

[Rodney]

Generally, no, no polarization on coil type relays. You might find some with a built in suppressor that could be polarized but I doubt it as most of these are external components.

[jollyrgr]

Joe29...<p>Most relays do not care which way you inject the power. BUT THIS IS NOT ALWAYS THE CASE!!! Many automotive relays have integrated diodes to quenche the EMF spike when the coil is de-energized. Here is one such example:<p>http://www.wiringproducts.com/index.htm ... lang=en-us<p>Thow an ohm meter across the coil and note the reading. Then reverse the meter lead connections and note the reading again. If you get a high and low reading then there is a diode. Connect the DC supply to the coil in the polarity indicated by the HIGH reading. In other words you want to put the positive voltage from the DC supply to the coil connection that the red meter lead is going to during the high Ohm reading. Is that clear as mud?<p>Since you knew to ask about this I think you can figure out the rest. If not, post back and I'll (or someone) will answer your question.

[philba]

In addition to the above, single coil latching relays have polarized coils. energize the coil one way, the relay latches; energize it the other way and it unlatches.