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How to make a relay slow release ?

 

I'm? going? to? use a? resistor to? slow? down a blower....on? RX.? ? ?Resistor? shunted? on? TX.....? with a DPST - NO Kilovac vac? relay.? (contacts in? parallel).
(12? vdc? coil,? 500? ohm? coil? resistance).??

I? want? to? make? the? relay slow? release,? like? .75? to? ?1 sec? release.? ?I? was? thinking of? a RVS? connected? diode? across? the? coil,
+ an? electrolytic? across? the? coil.? Electrolytic? wired? with? same? polarity? applied? to? coil.? ?10,000uf? to? 25,000uf? ?(on? paper)? should? work.?

The? idea? is? to? keep? the? blower at? max? speed? during? TX,? even? when? VOX? drops? out.? ?Typ I? use .375 sec? vox? delay.

Jim? VE7RF? ?
 

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Wouldn't just the inertia of the blower itself provide almost the same delays you are desiring?

Joe WB9SBD

The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com

On 2/26/2020 11:56 AM, Jim VE7RF wrote:

I'm? going? to? use a? resistor to? slow? down a blower....on? RX.? ? ?Resistor? shunted? on? TX.....? with a DPST - NO Kilovac vac? relay.? (contacts in? parallel).
(12? vdc? coil,? 500? ohm? coil? resistance).??

I? want? to? make? the? relay slow? release,? like? .75? to? ?1 sec? release.? ?I? was? thinking of? a RVS? connected? diode? across? the? coil,
+ an? electrolytic? across? the? coil.? Electrolytic? wired? with? same? polarity? applied? to? coil.? ?10,000uf? to? 25,000uf? ?(on? paper)? should? work.?

The? idea? is? to? keep? the? blower at? max? speed? during? TX,? even? when? VOX? drops? out.? ?Typ I? use .375 sec? vox? delay.

Jim? VE7RF? ?

 

¿ªÔÆÌåÓý

Slow delay also equals slow pickup unless you add another relay contact.?

Don W4DNR?

-------- Original message --------
From: Jim VE7RF <jim.thom@...>
Date: 2/26/20 11:56 AM (GMT-06:00)
Subject: [ham-amplifiers] How to make a relay slow release ?

I'm? going? to? use a? resistor to? slow? down a blower....on? RX.? ? ?Resistor? shunted? on? TX.....? with a DPST - NO Kilovac vac? relay.? (contacts in? parallel).
(12? vdc? coil,? 500? ohm? coil? resistance).??

I? want? to? make? the? relay slow? release,? like? .75? to? ?1 sec? release.? ?I? was? thinking of? a RVS? connected? diode? across? the? coil,
+ an? electrolytic? across? the? coil.? Electrolytic? wired? with? same? polarity? applied? to? coil.? ?10,000uf? to? 25,000uf? ?(on? paper)? should? work.?

The? idea? is? to? keep? the? blower at? max? speed? during? TX,? even? when? VOX? drops? out.? ?Typ I? use .375 sec? vox? delay.

Jim? VE7RF? ?

 

< Joe WB9SBD
Feb 26???

< Wouldn't just the inertia of the blower itself provide almost the same delays you are desiring?

##? I? thought? about? that..after I posted !? ?Point? well? taken.? ?I? will? test on bench...and? time? how? long? it? takes? to? spool? down....and? also? spool? back? up? to? max? rpm.? I? suspect? the? spool? up? time? will? be? a lot? faster..vs? spool? down? time.?

Jim? VE7RF
 

<Don Roden
Feb 26???

<Slow delay also equals slow pickup unless you add another relay contact.?
?
<Don W4DNR?

##? I? had? thought? of? that scenario.? A? 25,000 uf cap,? charged? up to? 12 vdc? =? 1.8? joules? (1.8? watts? for? 1? second).?
12 VDC vacuum? relay,? with a 500? ohm? coil? =? .288? watts.?
?1.8 / .288 =? ?6.25? seconds slower? release time.

##? I? will? measure? both? the? 'pickup'..and also...'dropout' vdc? of? the vac? relay.? ?I? suspect? both? will? be? far? less? than? 12? vdc.

##? On? paper,? the? 25,000 uf? cap? should? charge up very? fast,? almost? instantaneously.??

##? Relay? in? question? is? the? kilovac? DPST-NO,? sold? by Ameritron /? MFJ.? ? PN 408-8100, $19.95? ?(page? 76? in? 2020? online? catalog).?
5? kv? @? 10A? contacts. (5A? RF). So? will? parallel? the? contacts..and? turn? it? into a hd? SPST? 20A? CCS? rated fast? vac? relay. Those? relays? are? cheap? from? ameritron.?I'm? gonna? use? one to? shunt? out? the? 50? k? resistor in? the? CT? of? fil? xfr.... on? TX.?

Jim? VE7RF
 

How much relay pitting would you get at 25,000 uf ?
A little more complicated, but a 555 timer with a adjustment knob
might let you experiment a little more with hang time.

Don W4DNR

Quoting Jim VE7RF <jim.thom@...>:

<Don Roden
Feb 26 #37161 ( /g/ham-amplifiers/message/37161 )

<Slow delay also equals slow pickup unless you add another relay contact.

<Don W4DNR

##? I? had? thought? of? that scenario.? A? 25,000 uf cap,? charged?
up to? 12 vdc? =? 1.8? joules? (1.8? watts? for? 1? second).
12 VDC vacuum? relay,? with a 500? ohm? coil? =? .288? watts.
1.8 / .288 =? ?6.25? seconds slower? release time.

##? I? will? measure? both? the? 'pickup'..and also...'dropout' vdc?
of? the vac? relay.? ?I? suspect? both? will? be? far? less? than?
12? vdc.

##? On? paper,? the? 25,000 uf? cap? should? charge up very? fast,?
almost? instantaneously.

##? Relay? in? question? is? the? kilovac? DPST-NO,? sold? by
Ameritron /? MFJ.? ? PN 408-8100, $19.95? ?(page? 76? in? 2020?
online? catalog).
5? kv? @? 10A? contacts. (5A? RF). So? will? parallel? the?
contacts..and? turn? it? into a hd? SPST? 20A? CCS? rated fast? vac?
relay. Those? relays? are? cheap? from? ameritron.?I'm? gonna? use?
one to? shunt? out? the? 50? k? resistor in? the? CT? of? fil?
xfr.... on? TX.

Jim? VE7RF
 

25k? uf? ?cap? is? only? charged up? to? 12? vdc...? = lousy 1.8? joules.? ? Cap? in parallel? with? 12 vdc? coil.?

Relay? contacts? wired? across? the? drop? resistor? to? blower.? Drop? Resistor inserted? in? series? with? one? leg? of? the? 230 vac? small blower.?

A? 555? is? another? option.?

Jim? VE7RF
 

I? could? also? wire a small? 250 vac? rated MOV? across relay? contacts.

Jim? VE7RF
 

HD? opto? isolator? will? be? used? to? activate? the? 12? vdc? vac? relay? coil.? Opto's output? side? is? just? a solid? state SPST? device.? I? can? activate several? vac? relays, if? required, with just? one? opto.

Jim? ?VE7RF??

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