Polarized Relay Coil - Diode needed?

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#1
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I'm using this DPDT relay - http://pewa.panasonic.com/pcsd/p...

The datasheet states that the coil is polarized, but the schematic shows a simple coil.

I'm guessing that the coil is polarized by the addition of a diode across the coil, but nowhere does it state this. In my current design I have external diodes in parallel with the coils of the relays. I'm getting ready to order more boards and I'm trying to clean the board up a bit, without degrading the performance of the circuit. All of the boards will be hand soldered so I'm looking for minimal component count. Should the diodes stay or go?

Thank you,

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Kevin Pierson

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Stay

The "polarized" relays I have used are magnetically polarized, meaning they will only function mechanically if the current flows in the correct direction. You still need the diode if you want protection from the flyback.

Tom Pappano
Tulsa, Oklahoma

edit: Looking at your post closer, that DS2 relay is the very one I'm using

Tom Pappano
Tulsa, Oklahoma

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You need the diode like with any other DC coil relay, your relay just seems to need + at pin 1 and - at pin 16 to work.

- Jani

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So its a solenoid coil around a permanent magnet plunger, rather than a solenoid around an iron plunger? I assume this design is more expensive, but has other advantages? Is it double acting? Can go in or out under two polaritys? More torque (electromagnet flux + permanent magnet flux)?

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