John wrote: "50% isn't bad. It will guarantee that most relays hold closed, and cuts power by 4:1. "
Translation: most relays' specs guarantee that they will stay pulled in at half current.
The word "most" means, not all, so check your relay's specs to be sure this rule-of-thumb applies.
Nothing wrong, confusing, misleading, or inappropriate about that statement.
Cheers, James Arthur
Yes, mentioned in another recent thread, precursor to this one.
Cheers, James Arthur
Sounds about right.
Agreed, and relays too, for that matter.
There's a pile of gold out there from the survival-types for the first relay-based EMP-safe web-browsing laptop able to survive Iranian nukes.
:-)
Cheers, James Arthur
-- But irrelevant, yet couched in terms designed to cast you in the role of an authority.
John... Please, please, please, let's not go there again.
George H.
o
et
lIt's not John guaranteeing. Most *relays* are guaranteed (by their makers), etc., etc. Not by John.
Wouldn't one fall *into* a pitard (one's own or otherwise), rather be hoist up?
Grins,
James Arthur
Oh please yes! Let's debate the meaning of infinity, ad infinitum!
Vital follow-ups: Isn't Buzz Lightyear's catchphrase false advertising? Where's the outrage?
And then we can quibble over whether latching relays actually latch...
Cheers, James Arthur
I think Fields has gone senile on us... he just won't learn that an unfed troll gathers no podium. ...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Hmm is that a countable infinity? Or uncountable.... (I'm not sure I have enough time for an uncountable infinity :^)
George H.
And here I was thinking it was a really dumb but vicious dog...
--sp
-- Best regards, Spehro Pefhany Amazon link for AoE 3rd Edition: http://tinyurl.com/ntrpwu8 Microchip link for 2015 Masters in Phoenix: http://tinyurl.com/l7g2k48
A graduate student at Trinity computed the square of infinity but it gave him the fidgets to write down the digits so he dropped math and took up Divinity
--sp
-- Best regards, Spehro Pefhany Amazon link for AoE 3rd Edition: http://tinyurl.com/ntrpwu8 Microchip link for 2015 Masters in Phoenix: http://tinyurl.com/l7g2k48
Chicken!!!!
I posted a cute little circuit for discussion, as I often do. You whined about me (not it), as you always do.
And you don't seem to be interested in relay behavior, not enough to do a little research and actually contribute.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
I wonder if there is any DC em relay that isn't guaranteed to hold closed at 50% of rated coil voltage. I've never seen one.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Those flipflop oscillators and one-shots are cute. Do you think they're reliable?
I've made one-shots from flops with feedback delays from Q or Qbar into the clear input. Classic TTL flops with RC delay didn't usually work: the flop hung in some mid-logic-level state. It usually works with short delays in CMOS and ECL.
Some higher-order delay, RLC or an actual delay line, is safer, but it's hard to get a millisecond-range delay that way.
A few gates make a nice delay line here, but not milliseconds.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
I must apologize for inciting this diversion.
My input didn't have anything to do with relays. I commented on COMMUNICATION and the use of the word "guarantee" to describe something clearly not guaranteed in the general case.
I have no quarrel with the concept of reduced hold-in current. "Look it up" was a more helpful statement.
I even misquoted my own favorite nonsense newspaper ad. The correct nonsense ad text was: "Up to 50% off or more"
The correct phrase is hoist with, not on:
The meaning is to hurt one's self while intending to hurt others.
"For tis the sport to have the enginer Hoist with his owne petar".
So "engineer" was in use in 1602. No mention of relay coils.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
-- If you want to be thorough, you need to look at the hold voltage and all of the conditions under which the relay is expected to operate. Considering ambient temperature, the increase in coil resistance and the attendeant diminution of coil current - for a fixed voltagte across the coil - because of temperature rise in the coil due to I^2 R losses is one factor, and vibration/shock is another. Most garden-variety relays are guaranteed to pull in at 75% of their rated coil voltage and drop out at 25%, so for a relay with contacts which have been made and then had its coil voltage drop by 50%, a great enough shock will cause the armature to drop below its event horizon, breaking the contacts and causing them to remain broken. John Fields.
-- The language has changed a little over the last 413 years, but the meaning remains evident.
That bites.
--ja
Depends. Is that an African, or a European infinity?
Cheers, James Arthur
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