I control my latching relays with one control line plus ground. It requires
two voltages [+ / - ] and a simple RC circuit in each + and - source used to
feed the control line for the relay.
The RC circuits provide a big current pulse when switching and then limit
the current to a much lower value once the transition has taken place.
Sent via my DROID X
From: Jim Thomson <firstname.lastname@example.org>
Sent: Mon, Dec 27, 2010 08:40:22 GMT+00:00
Subject: [TowerTalk] Gigavac Relays
Date: Sat, 25 Dec 2010 20:53:40 -0800
From: "Richard (Rick) Karlquist" <email@example.com>
Subject: Re: [TowerTalk] Gigavac Relays
On 12/25/2010 6:52 AM, Howard Hoyt wrote:
> Howdy and Merry Christmas all,
> I maybe restating common knowledge here, but I just discovered that
> Gigavac has a special program to sell HV/RF relays to hams directly at a
> really reasonable cost:
I can report that the ham purchase program works as advertised
for about $85. I bought the 12V version and rebuilt
my homebrew QSK circuit for my linear. I used the speed up circuit
Using this, the turn on time is less than 5 ms.
Although this circuit doesn't speed up release,
it was already under 10 ms.
The whole thing runs on +12V including the reed
relay for the radio.
I had previously used Rich Measures' QSK circuit,
which was very inconvenient because it required
100V, which I didn't happen to have (my linear runs on 48V).
I kept the reed relay from that circuit to use in the
new one. BTW, the reed relay doesn't need any speed up.
It's something like 2 ms from the factory.
The 28V vacuum relay in that circuit failed.
I had bought it surplus, used. I think its worth the
extra money to get a new one.
The dimensions of the current relay are slightly different
from my old surplus one. I had to slightly enlarge the
mounting hole. They converted to metric dimensions.
The new relay still has the same flimsy coil connections,
be real careful you don't bust them off.
### BTW, I talked to the Gigavac eng a few yrs back...and although the
'ham' version of
a G-2 , GH-1, and G41 and G-12 all are depicted with lower peak V and
lower CCS RF current ratings,
such is NOT the case per the gigavc eng I talked to. The G2 and G2-ham
have IDENTICAL specs. The ham
version is "de-rated' to appease commercial user's, so they don't think
they are being ripped off. Max gain
systems sells the GH-1 for less than the Gigavac GH-1 ham version
anyway....and no max limit of 3 x relays per
yr either. The Kilovac version is far mote robust than the jenning's
RJ1-A.... which is why Alpha switched from
jenning's to kilovac years ago. The gigavac version is better than both
of them. The GH-1 will consistently hi-pot
test to > 7.5 kv. Max gain systems has excellent pricing on the entire line
of gigavac relays, including the G23, G52, G-9
## Kilovac engs told me years ago, If you are limited with vdc...and you
want to speed up a 26.5 vdc relay.... then simply
use the 12 vdc version instead. With 24-30 vdc applied with a simple drop
resistor..they operate blazing fast. If you want em still
faster, then use a small 50 uf lytic across the drop resistor, then it
becomes a 'RC hot shot circuit' . If you have +48 vdc available,
you are laughing.
## I had no problems with building a +120 vdc supply, using a FWD..for
use with speeding up a 26.5 vdc vac relay. I use a
P+B ODC-15 or ODC-15A opto isolator..with a 8-18 vdc input. The opto
has 4 kv primary to sec isolation, and operates in < 100 microseconds.
RlS time of the same opto is 750 microseconds. Current draw on the 12 vdc
opto primary is just a few ma.
## For applications for ant use..such as the ultimate trbl free remote
ant switch box's.... or for shorting out coils at the feed-point of DE's,
etc... you can get many of the gigavac relays in a latching version. I
find the 'hold' voltage [ min voltage to operate a vac relay] to be low
that I usually don't bother with the latching version. The latching
versions all use 2 x coils. With a com between em... you still require a
min of 3 x control leads to operate em. Any 13.8 vdc supply will work with
them. You can also get many of the gigavac relays in either a threaded
base or a flanged base. You can also get many of then with threaded
cylinders... instead of soldering... which makes using strap or sta-kon
Later.... Jim VE7RF
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