Computing stuff tied to the physical world

Relay Plug stocks

In Hardware on Sep 30, 2010 at 00:01

As it turns out, this slim-line relay (Conrad #504286, PCN-105D3MHZ) is not available until April 2011 (gasp!) … no matter where in the world I look:

Dsc 1813 2

Fortunately, there is an equally-slim replacement with the same footprint (thanks, Lennart!):

Dsc 2007

It’s a bit higher, and it handles a bit more current (up to 5A):

Dsc 2008

I’ve ordered a bunch of these, but I also need to get a new batch of PCB’s – didn’t want to order them without a chance of getting suitable relays (Conrad #502047). The new plugs won’t be here before mid-October. And the new relays are a bit pricier, so I’ve had to raise the price of the kit a bit.

Atoms, oh atoms … why can’t you be more like bits? As in: no stocks to worry about?

  1. Hello,

    If you use relays to switch 220V and larger current, it’s wise to switch the relay on Voltage zero crossing, keep in mind a relay is also slow, useally around 5ms. So 5ms before the real zero crossing, teh relay should already be activated.

    May a circuit could be build for this. To sense zero crossings.

    The issue is if you switch the relay through a peak of voltage, a big inrush current of the load is put trough the relay contacts, which gives a spark. Which leads to bad contact at a certain point. You do have self cleaning contacts but those a quite expensive.

    Hopefully this info could be usefull to somebody.


    • Thanks – that’s a great tip. I’m still looking for a simple way to detect the zero crossing in the mains power line. Could we just pick up the magnetic field with a little coil perhaps (tuned to 50/60 Hz preferably), and tweak for the proper phase in software? And maybe this weblog post has some use here?

Comments are closed.