BK Precision 1655A AC Power Supply

[jwrtiger]

I have done a little review of the BK 1655A isolated-variable AC Power Supply.  I also did a little tutorial background associated with this type of supply.  It is on my jwrelectro YouTube channel.  I am a hobbyist so hope others getting started will find it helpful.

[radhaz]

Very nice usage review of such supplies, thanks for posting.

[jwrtiger]

Thank you and glad you enjoyed the video.

John

[GAD]

Thanks for the video! I really liked your schematics showing the dangers possible with DUTs and scopes.

One of the things I really dislike about these units is the fact that the leakage probe isn't removable, and as you stated has terrible strain relief. I hate wires that I can't put away and that probe drives me nuts.

The BK Precision model has three-prong plugs on the isolation side. Are the ground pins on these outlets grounded to the chassis? 

[jwrtiger]

Your welcome and glad you liked the video.  Yea a plug for the leakage probe might be a nice feature.  Yes the dual AC sockets on the front panel have the ground receptacle connected to the chassis of the unit which is connected to earth ground via the AC power cord.  The simplified diagram shown in the video is basically the BK AC power supply.  If that earth/neutral  ground connection is a problem a ground plug adapter can be used to float the device under test as long as safety is considered.  Again thank you for your comments... much appreciated.

[GAD]

Your welcome and glad you liked the video.  Yea a plug for the leakage probe might be a nice feature.  Yes the dual AC sockets on the front panel have the ground receptacle connected to the chassis of the unit which is connected to earth ground via the AC power cord.  The simplified diagram shown in the video is basically the BK AC power supply.  If that earth/neutral  ground connection is a problem a ground plug adapter can be used to float the device under test as long as safety is considered.  Again thank you for your comments… much appreciated.

Thanks. The reason I ask is because the guts of the BK look very similar to the guts of this old unit I bought: https://www.eevblog.com/forum/testgear/vector-vod-iso-v-ac-iii-wp-32-variable-isolation-transformer/

The Vector Vid is larger because it's 10A, but the underlying principals are the same (as you'd expect).

I was actually considering the purchase of one of these BKs to tear it apart for comparison, but with your pics and review I don't need to.

[jwrtiger]

GAD, please note there are pictures of the BK unit on my website under Reviews if you need a closer look then the video offers.  tigermultimedia.com

[calin]

So I was looking for an isolation transformer, found on Craigslist an BK Dynascan 1655. Looks and well IS a BK 1655A. I got the thing for 80$ .. sweet.


Many thanks for the photos on your site, the oldie and the young one are very very similar if not identical from as much as I can see. I-ll put some pictures up when I have time.

[gboutique]

Hello everyone, I have a B & K model 1655 (the previous version), and I think I have a problem. Setting the output voltage at a120Vac, and measuring with a multimeter the voltages in the double output connector, I get the following voltages AC; live to neutral 120Vac, live to ground 144.7Vac and nuetro to ground 37.4Vac. Is this normal, or does it correspond to an equipment fault?

Thanks..!!