We have been using the various sizes of switchmode "brick" power supplies for some time now. When they'll fit, they provide a superior alternative to fixing the under designed linear-regulated supply and transformer found in a lot of base radios.
Imagine my surprise when my latest restock order arrived. It's the one in the baggie on the right. The size I have become accustomed to is on the left. A glance back at the listing photos reduced the surprise level. Hadn't looked too closely at first.
It's smaller in all three dimensions. And the connections are separated. AC-line input on one end, DC output at the other.
Inside it's a gutless wonder. Labor-saving measures you can see include plastic-encapsulated rectifier and MOSFET packages. Just like the familiar TO-220, but with the metal tab enclosed in the black body plastic. No need for insulators, just bolt 'em down with a dab of compound underneath. The real complexity is most likely a bunch of surface mount stuff on the underside of the circuit board. Didn't tear it that far down.
Naturally, the first thing to look for is the voltage-adjust trimpot. The customer will want it turned up as high as it goes.
Had to lift the top cover to find it. There's an adjustment hole in the cover, but no trimpot under it.
Now it's easier to access with a hole punched above the trimmer.
Full disclosure: I haven't plugged one in to try, yet. If it's a disappointment, I'll want to pass that along, as well.
73
Imagine my surprise when my latest restock order arrived. It's the one in the baggie on the right. The size I have become accustomed to is on the left. A glance back at the listing photos reduced the surprise level. Hadn't looked too closely at first.
It's smaller in all three dimensions. And the connections are separated. AC-line input on one end, DC output at the other.
Inside it's a gutless wonder. Labor-saving measures you can see include plastic-encapsulated rectifier and MOSFET packages. Just like the familiar TO-220, but with the metal tab enclosed in the black body plastic. No need for insulators, just bolt 'em down with a dab of compound underneath. The real complexity is most likely a bunch of surface mount stuff on the underside of the circuit board. Didn't tear it that far down.
Naturally, the first thing to look for is the voltage-adjust trimpot. The customer will want it turned up as high as it goes.
Had to lift the top cover to find it. There's an adjustment hole in the cover, but no trimpot under it.
Now it's easier to access with a hole punched above the trimmer.
Full disclosure: I haven't plugged one in to try, yet. If it's a disappointment, I'll want to pass that along, as well.
73
