Homebuilt ROVs Forum

thegadgetguy wrote: I saw a few other relays that might work on that website:

http://www.rapidonline.com/Electronic-C ... es-60-4172
http://www.rapidonline.com/Electronic-C ... 82-60-4384
http://www.rapidonline.com/Electronic-C ... 22-60-4380

The second two are basically the same relay, as far as I can tell. They appear just to have different types of contacts on the bottom. They all look decent to me. What do you think scubersteve?

out of all those, I like the first one the best and the 10A rating is probably fine even if you were to pull 12A through it on occasion. It's cheap too. Small pins though.

However, I like these better...
http://www.ebay.com/itm/5-PAIR-12-VOLT- ... 3f23c2e9f6

it says they ship worldwide too.

Those relays are only single pole, so you would need 4 per thruster, instead of two double pole ones. They look like they would work otherwise, though.

Shipping something from Alabama to UK/English Channel can't be cheap. Did you say that Rapidonline had reasonable shipping rates to where you live, AHarris? Are there any other places that you'd like to order from?

Hah!
You're right!
Silly of me to have overlooked that.

You do only need two single pole to connect one thruster. I can upload a shematic if you are interested.

RapidOnline offer some very good shipping rates, orders under 1kg but over £25 are free and other 1kg is £9.00, meaning you could order 10kg worth of stuff and it all will only cost £9.00 shipping.

I have found another PVC manufacturer online which is also cheaper, so I've managed to bring my cost down a bit. However you are right, shipping from the US isn't cheap, I think I was quoted £100 ($153) for a couple of DPDT switches, before I found some on Amazon.

Thanks for the links, I did spot the 12V 10A one, however it has a minimum order of 100.


Thanks for all the help!

I've submitted a support query to RapidOnline, since they have a group of technicians who answer questions relating to products, to see if it is possible to switch a 24V DC relay with 12V.

http://www.rapidonline.com/Electronic-C ... Dc-60-1673

I'm looking at definitions at the moment, and the Min Switching Load is described as

This value is a guideline as to the lowest possible level at which it will be possible for a low level load to allow switching.

whereas the coil voltage is described as

A single value (or narrow range) of source voltage intended by design to be applied to the coil or input.

So it would appear that 24V is what it is rated for, in a normal situation (and the max voltage that can be applied to it) and 1V is the minimum it shall work at.

I use this shematic for my ROV with a single pole relay. Then you can control one motor both ways with use of two control wires down to ROV.

You can find cheap single pole relays on this page http://www.taydaelectronics.com/mini-re ... ntact.html Only 0,64 UDS each. I have use these for my designs and they work perfect. Fast shipping as well.

You could use the following Panasonic act212 this is a 12v h bridge relay ie only one required for fwd and rev I use them with converted bilge pumps and they work well I bought some from rs components and some of ebay. Check the specs at rs components to see they meet your needs.

Cheers
Jonnyhas

Thank you for the suggestions, and the wiring diagram. The concept of using single pole relays is an intriguing one, however I shall need to look at that wiring diagram more closely to see if it is a suitable one, not being able to read them fluently it shall take me a while but it might be something well worth considering.

Thanks!