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Topic: Controlling two cold cathodes - is this possible? (Read 3297 times) previous topic - next topic


If you use an electromechanical relay make sure you order a diode too to put across the coil:


The Quick Shield: breakout all 28 pins to quick-connect terminals


Google found this sheet
which says it's an SSR after all.

So I just got to order the SSR?


Click on the link at the center-top of the page you found that says "datasheet"  :)   The datasheet (always more trustworthy than what the distributor says) says it's electromechanical.

Diodes are cheap, buy some anyways. You can use them for Christmas decorations if nothing else.

Need a custom shield? Let us design and build one for you.


from page 3 of data sheet - see also p.2 (graphics broken, naturally )

Ordering information
Electromechanical relay (EMR)
Example: 34 series slim electromechanical relay, 1 CO (SPDT) 6 A contacts, 24 V sensitive DC coil.
                                                                               A      B        C    D
                                                                                      0        1    0
                 3 4 . 5                1 . 7 . 0 2 4 . 0
                                                                A: Contact material                 D: Special versions
                                                                0 = Standard AgNi                   0 = Flux proof (RT II)
                                                                4 = AgSnO2                          9 = Flat version
5 = Electromechanical type
                                                                5 = AgNi + Au (5 [ch956]m)                C: Options
No. of poles
                                                                                                    1 = None
                                                                B: Contact circuit
1 = 1 pole, 6 A
                                                                0 = CO (SPDT)
Coil version                                                    3 = NO (SPST)
7 = Sensitive DC
Coil voltage
See coil specifications
Selecting features and options: only combinations in the same row are possible.
Preferred selections for best avaliability are shown in bold.
  Type     Coil version   A           B           C           D
  34.51    sens. DC       0-4-5       0-3         1           0
  34.51    sens. DC       0-4-5       0           1           9
Solid state relay (SSR)
Example: 34 series SSR relay, 2 A output, 24 V DC supply.
                3 4 . 8                 1 . 7 . 0 2 4 . 9 0 2 4
                                                                                    Output circuit
                                                                                    9024 = 2 A - 24 V DC
                                                                                    7048 = 0.1 A - 48 V DC
8 = SSR type
                                                                                    8240 = 2 A - 240 V AC
1 = 1 NO (SPST-NO)
Input circuit
See input specifications


Sep 12, 2010, 11:21 pm Last Edit: Sep 12, 2010, 11:23 pm by mpeuser Reason: 1
There is little consistency in all those information.

The price of $19 horrible. But high end SSR go for that. A medium current electro-mechanical relay would be around $5...

A MOSFET is < $1.

Indeed, I lost the rationale behind this thread in the meantime...


Finder part number "" is SSR
34.51.whatever is electromechanical
in case it is not clear to someone.
The finnish site link is to an SSR

i'd go to discrete too, for what it matters


Finder part number "" is SSR

It clearly said SSR when I ordered it, so that's what I am expecting. If get the wrong part I am going to return it obviously.


I just got a mail from Partco, telling that they don't have the relay I ordered. There was some kind of error in their indexing. Anyways I'm trying to find yet another fitting SSR/EMR for my project. Now im looking into small relays. This one seems fitting, what do you guys think?


Look for a Reed Relay with integrated diode, if 1A switched current is enough for your application.

All other things require some experience...
5VDC 165[ch937]

You do know what that means?


Sep 13, 2010, 01:32 pm Last Edit: Sep 13, 2010, 01:44 pm by virtuoosi Reason: 1
You do know what that means?

5VDC is the required activating input voltage. Eg. the output of my Arduino board.

1A 24VDC is the voltage/current the relay will control. The voltage I'm trying to control is actually 12VDC, but that's not a problem, right?

1A is enough. The current is somewhere around 800mA.

EDIT: I found a 1A 5VDC reed relay with diode. Also read about the working principles of a reed relay. I think I got it now.

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