What is this component? GI - Relay - GI 2306 603M

Thread Starter

zirconx

Joined Mar 10, 2010
96
I have been looking for some small, cheap, relays I can drive directly from arduino & raspberry pi boards. Capable of switching 250ma would be great, but would settle for less.

I came across this, it's cheap, but there is no spec sheet and I don't really even know if it's a relay. Anyone know what this is? My googling isn't turning up anything.

https://www.alltronics.com/cgi-bin/item/2306_603M/search/GI-Relay---GI-2306-603M

 

MisterBill2

Joined Jan 23, 2018
4,564
Neither the transistor nor any of most logic gates provide any isolation at all. So neither will do what you need. There are some reed relays that look a lot like 14 or 16 pin ICs, except that they have only 4 leads in the corner positions. Some of those also include a diode across the coil, which makes them very polarity sensitive. There are also reed relays that do not look like IC devices and some of them may be sensitive enough to work with an arduino. AND they will provide good isolation.
 

sagor

Joined Mar 10, 2019
126
Some simple reed relays can be driven by most micros. I've used SIP-1A05 types to switch either DC or AC circuits that are not real heavy loads.
Those are often rated 10W for the contacts, switching 0.5A or 100V maximum (but not both of those). The 10W rating is a limiting factor. 0.5A should not have more than 20V, at 100V, max current would be 0.1A
Isolation between coil and contacts is 1400VDC (1000VAC RMS). Closure and open time is around 0.5ms
With one of my PIC circuits, those relays draw about 10mA at 5V, which is within specifications for most micro chips.
 

SamR

Joined Mar 19, 2019
1,507
I distinctly remember something about a cheap relay for 250mA. And the 2n2222 is quite capable of that and a very common and extremely cheap device for using with a logic 5V input to switch a higher voltage with an Arduino. Much cheaper than any relay I could recommend. Max mentioned the 2N7000 but it tops out ~200mA but has a bigger brother in the TO-90 size the BS170 which are also pretty cheap and use very little to drive them. I can buy 50 2N2222's for what a relay costs.
 
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MisterBill2

Joined Jan 23, 2018
4,564
It is always good to isolate the CPU board from external voltages, and because the TS started by asking about relay types I do not consider it reasonable to recommend a totally different kind simply because it is cheaper, since it is also totally different as far as isolation. The exact words were "small cheap RELAYS" That sounds like isolation to me.
 

MaxHeadRoom

Joined Jul 18, 2013
19,451
It is always good to isolate the CPU board from external voltages
The device shown in the OP does not provide isolation, I have been using mosfets in preference to bi-polar since their inception when working with logic and micro's and so far have not really found any down side, I use the 2n7000 to drive a mechanical relay if necessary as the output of the logic/micro often will not drive the relay directly.
I think I took to Mosfets as they remind me of their predeccessors, the electronic tube!
Max.
 

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MisterBill2

Joined Jan 23, 2018
4,564
The device shown in the OP does not provide isolation, I have been using mosfets in preference to bi-polar since their inception when working with logic and micro's and so far have not really found any down side, I use the 2n7000 to drive a mechanical relay if necessary as the output of the logic/micro often will not drive the relay directly.
I think I took to Mosfets as they remind me of their pre-decendents, the electronic tube!
Max.
Certainly a mosfet can be a good switch, but more certainly they provide no isolation between the driving circuit and the switched circuit. Especially with small board computer things isolation is important.
 

MaxHeadRoom

Joined Jul 18, 2013
19,451
Of course, but they can offer interface to other devices such as more common 12vdc/24vdc relays, solenoids etc and provide the drive power that the Micro etc, does not have.
The OP does not specify what he wants to drive, just that "Capable of switching 250ma would be great, but would settle for LESS."
Max.
 

Thread Starter

zirconx

Joined Mar 10, 2010
96
...The OP does not specify what he wants to drive, just that "Capable of switching 250ma would be great, but would settle for LESS."
Max.
One project is an ardiuno controlling an LED "toy" stop light (I already purchased the stop light, found at a thrift shop). Each light consumes around 100ma.

But I was also asking the question related to all my projects in general, when I need to turn something on from a micro controller or raspberry pi.

I do have some transistors I bought a while back for this purpose, MPSA92's which can switch 500ma. I'm still pretty new to this and I find it easier to use a relay, since I don't have to calculate resistor values, make sure the transistor is saturated, but not passing more current than is necessary to be saturated, etc. I'm not sure if I can even fully saturate it with a 3.3v raspberry pi, which can output a max of 15ma. But perhaps the transistor still is the best option and I just need to spend more time investigating & planning.

Thanks for the responses.
 

SamR

Joined Mar 19, 2019
1,507
Try it and see what happens! That's one way to learn... It never hurts to have a few 2n2222s and NE555 timers lying about. Oh and always look at the PDF before using a part. You just might learn a thing or 2.
 
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MaxHeadRoom

Joined Jul 18, 2013
19,451
Each light consumes around 100ma.

But I was also asking the question related to all my projects in general, when I need to turn something on from a micro controller or raspberry pi.

I do have some transistors I bought a while back for this purpose, MPSA92's which can switch 500ma. I'm still pretty new to this and I find it easier to use a relay, since I don't have to calculate resistor values, make sure the transistor is saturated, but not passing more current than is necessary to be saturated, etc. I'm not sure if I can even fully saturate it with a 3.3v raspberry pi, which can output a max of 15ma. But perhaps the transistor still is the best option and I just need to spend more time investigating & planning.
That is the beauty of the Mosfet, For most 5v logic you only need the gate pull up resistor, if at all, (see the 2n7000 example app sheet I posted).
The Mosfet is voltage driven, trans conductance amp, just needs the correct gate voltage, hence the logic level gate versions.
The 2n7000 for ~50¢ ea.
Also see IRL540.
I can't remember the last time I used a Bipolar version.
Max.
 

SamR

Joined Mar 19, 2019
1,507
I'm still working on making the BJT to MOSFET conversion but the BS170 N-channel MOSFET can take 200mA @ 60V up to 830mW for $0.81/10. The BJT 2N2222A NPN can take 800mA @ 40V up to 500mW for $1.02/100. Both good and cheap TO-90s for most low volt DC hobby work. Obviously, the MOSFET takes less overhead. While I'm at it the 8-pin DIP NE555 is $0.70/20 or $1.01/50. All good learning tools for an introduction to semiconductors along with a few diodes. Plus you can play around with amps with the 2n2222a, not sure about the MOSFET amps. Still plenty for me to learn about MOSFETs.
 
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