8 Dec
2021
8 Dec
'21
1:58 p.m.
-----Original
Message-----
From: cctalk <cctalk-bounces at classiccmp.org> On Behalf Of Jay Jaeger
via cctalk
Sent: 05 December 2021 14:51
To: cctalk at classiccmp.org
Subject: Re: PDP-11/70 Boards
On 12/5/2021 3:37 AM, Rob Jarratt via cctalk wrote:
From the schematics, some of them seem to want 20-30 VAC (some, like
at least one of the -15v regulators, take DC inputs from other
regulators)
For lower current initial testing I have some 24v 2A transformers
lying around. For higher current, I might use something like this guy:
https://www.digikey.com/en/products/detail/triad-magnetics/F-
401U/5032226
Thanks for the tips. The transformer that drives
the bricks is a real beast.
Did you find an alternative more convenient way to
power them on the
bench?
I have a variac rated at 2.5A. I am not quite sure
whether that would be
sufficient to test the bricks individually. Otherwise, I guess one of these
would do the trick https://cpc.farnell.com/block/steu250-48/transformer-
250va-230-400v-2-x/dp/TF01418?st=24v%20transformer ?
So, to supply the bricks on the bench, would a variac rated at 2.5A be OK? I am not sure I
know how much current the bricks will draw at 20VAC, and at what voltage the 2.5A rating
is given. Otherwise, would this do the trick?
https://cpc.farnell.com/block/steu250-48/transformer-250va-230-400v-2-x/dp/…
Thanks
Rob
>
> JRJ