Relay turn-off time

[Bennet Williams]

Does anyone know approximately how long it takes for the contacts on a
typical small DC ice cube relay to open after the coil voltage is
removed?

BRW

 

[CWatters]

<Bennet Williams> wrote in message
news:q627k09qc1gc067372lo2acp7357lsl70f@4ax.com...

Does anyone know approximately how long it takes for the contacts on a
typical small DC ice cube relay to open after the coil voltage is
removed?

Usually listed in the specs somewhere.

 

[Tony Williams]

In article <q627k09qc1gc067372lo2acp7357lsl70f@4ax.com>,
Bennet Williams <> wrote:

Does anyone know approximately how long it takes for the contacts
on a typical small DC ice cube relay to open after the coil
voltage is removed?

I've measured an average of 15mS for a quantity
of the type known as 'Continental Cradle' relays.
That was with a diode directly across the coil.

--
Tony Williams.

 

[Bennet Williams]

Thanks for the info. The data sheet for the relay did not have this
information.

BRW

On Sun, 12 Sep 2004 09:55:28 +0100, Tony Williams
<tonyw@ledelec.demon.co.uk> wrote:

In article <q627k09qc1gc067372lo2acp7357lsl70f@4ax.com>,
Bennet Williams <> wrote:
Does anyone know approximately how long it takes for the contacts
on a typical small DC ice cube relay to open after the coil
voltage is removed?

I've measured an average of 15mS for a quantity
of the type known as 'Continental Cradle' relays.
That was with a diode directly across the coil.

 

[Michael A. Covington]

You can measure this, very roughly, by wiring up the relay as a buzzer. I
usually get frequencies between 200 and 800 Hz.

 

[John Fields]

On Sun, 12 Sep 2004 17:38:01 -0400, "Michael A. Covington"
<look@ai.uga.edu.for.address> wrote:

You can measure this, very roughly, by wiring up the relay as a buzzer. I
usually get frequencies between 200 and 800 Hz.

---
Since the frequency depends on both the make and the break time you'd
have to (assuming they were equal) double the frequency and take the
reciprocal of that, no?

--
John Fields

 

[Harry Conover]

Bennet Williams <> wrote in message news:<q627k09qc1gc067372lo2acp7357lsl70f@4ax.com>...

Does anyone know approximately how long it takes for the contacts on a
typical small DC ice cube relay to open after the coil voltage is
removed?

BRW

I'm curious as to why you're asking this question.

Specs are specs, but while I don't know of a way to speed the drop-out
of the contacts, a simple diode and series resistor across the coil is
very effective in slowing the drop-out, as is "slugging".

Also, there is no typical "small ice cube" relay. Performance specs
are dependent on both the manufacturer and relay model number. (These
are usually available on the manufacturer's web site.)

If you have no specs available, you simplest solution (as another
poster has already suggested is the wire the relay as a buzzer and
measure the frequency. This should be sufficient to give you +/- 10%
estimates of the dropout time.

Harry C.