Relay contact ratings.

I'm laughing at the turn this thread took. If she installs her own circuit, she is modifying the thing with a non-oem part, regardless of what parts she uses in her circuit. Thus any concerns about fire/liability/insurance/local regulations apply. Doesn't matter if it's flame retardant, 240VAC rated, gold plated, whatever, the exposure is still there.

She has already indicated she would not use an automotive relay, so it's moot as far as her project is concerned. But I wonder, has anyone else here actually tested one of those relays at 240VAC? I have, and it worked fine, but I did not test to destruction, nor for dielectric strength or flammability.

Ed

yeah, over voltage, or excessive dV/dt, will turn them on, but couldn't subsequent over-current cause them to fail closed?

CD4060, CMOS logic, an R-C astable and a 14-stage divider chain in one DIP package, but not strong enough to drive a relay directly like an LM555 would be.

less risk of fatal electric shock, more risk of fire from overheating conductors.

You wouldn't say that if you ever see an outlet explode and blow a hole in the wall, when lightning hit the power line a mile away. I have. The noise was deafening, and scared the hell out of my grandparents & parents. It took out all the power on my grandparents farm, as well.

We have underground utilities here. Some years ago a lightning strike at a substation 4 miles away blew out numerous appliances, several PC's, a TV set, and every light dimmer in the house. ...Jim Thompson

nd

d.

Yes, i have, because they are cheap or free. I also use wire wrap wire for 110V main, they are good FUSEs. However, i would not use them for unattended applicants like fridge or furnace. And i definitely would not advice someone asking for help on usenet to use them.

s.

I also have dead microwave and furnace transformers. After installing MOVs and FUSEs on the primary, i only have to replace them rather than transformers. OEM transformers are ridiculously expensive too.

After my event, I installed a full-phase MOV block at the entry cabinet. ...Jim Thompson

s.

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But i don't need to protect the microwave transformer, which draw almost 10A. I put in the MOV and 1A fuse on the 12V controller transformer. Next is to drill and mount the fuse externally, which they should have done in the first place. I guess they would rather sell new microwaves then fuses.

Hey Phil, he's stolen your **'s tag! :)

How many big cans of Foster's can it hold? :-)

Well, the doctor said only one beer a day. ;)

Cheers

Phil Hobbs

"John Devereux"

... Phil

No problem, Sir. This is how beer is often consumed in Dortmund (Germany) where I grew up:

A su salud!

Sylvia,

Try a PICAXE 08M2 - it costs $2.50 in one off's and programs in BASIC. Software and examples are free from

The only stuff you need to program one is a serial port (RS232 or TTL level) and a resistor.

We have failed to address the fundamental truth that endless growth is impossible in a finite world.

Kill off non-productive socialists and you're left with LOTS of space :-) ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

Interesting. Thanks.

I'm tempted to combine the timer with the thermostat, a replacement for which I've been cursin..., er, I mean testing, today. (Sod's law subsection 3.1 - a fridge must always enter defrost mode while a person is attempting to adjust the upper and lower settings of a thermostat.)

Of course, I could just buy a new fridge.

Sylvia.