http://www.ebay.com/itm/Adjust...a:g:G-MAAOSwNSxU~Tow

WOW, it even includes a rectifier tube!

Description：

• Input voltage: AC/DC 9~48V(adjustable)
• Output voltage: 1.8~25V
• Output current: 3A MAX
• Rectifier tube: IN5408 brand new
• Step-down working mode, the output is lower than the input
• When the input voltage is 24 V, output range of 1.8 ~ 22V
• When the input voltage is 30 V, output is 1.8 ~ 25V
• Size(L x W x H ):  approx. 8 x 5 x 3 cm / 3 x 2 x 1 1/5 inch

Pardon me, I just found that really amusing, a throwback to the 1950's!

PLCProf posted:

Well, just to make your day.....What would you call this?

A modern version of this?

PLCProf posted:

gunrunnerjohn posted:

WOW, it even includes a rectifier tube!

Description：

• Input voltage: AC/DC 9~48V(adjustable)
• Output voltage: 1.8~25V
• Output current: 3A MAX
• Rectifier tube: IN5408 brand new
• Step-down working mode, the output is lower than the input
• When the input voltage is 24 V, output range of 1.8 ~ 22V
• When the input voltage is 30 V, output is 1.8 ~ 25V
• Size(L x W x H ):  approx. 8 x 5 x 3 cm / 3 x 2 x 1 1/5 inch

 

Pardon me, I just found that really amusing, a throwback to the 1950's!

Well, just to make your day.....What would you call this?

A four Ge diode octal tube generally used on balanced modulator design.

PLCProf posted:

cjack posted:

http://www.ebay.com/itm/Adjust...a:g:G-MAAOSwNSxU~Tow

I use a lot of units similar to these these and they work just fine. You can run a lot of stuff from just one unit. Note that these are AC input units, so you won't need your bridge rectifier!

I picked out a switcher since it has to regulate 4.5 vdc at up to 3 amps from around 25 peak rectified input. I use them and they barely get warm. Also some of the volt/amp combo meters with the internal shunt wired to them make an excellent way to adjust the output of the switcher.

http://www.ebay.com/itm/DC-100...%26sd%3D162214186093

gunrunnerjohn posted:

WOW, it even includes a rectifier tube!

Description：

• Input voltage: AC/DC 9~48V(adjustable)
• Output voltage: 1.8~25V
• Output current: 3A MAX
• Rectifier tube: IN5408 brand new
• Step-down working mode, the output is lower than the input
• When the input voltage is 24 V, output range of 1.8 ~ 22V
• When the input voltage is 30 V, output is 1.8 ~ 25V
• Size(L x W x H ):  approx. 8 x 5 x 3 cm / 3 x 2 x 1 1/5 inch

 

Pardon me, I just found that really amusing, a throwback to the 1950's!

Ha! One of my Kenwood transceiver schematics listed a thunder protector on the antenna input.

I use a power distribution board and plugs I found on ebay.  plug link: http://www.ebay.com/itm/10pair...r-CCTV-/381502157099  board:http://www.hobbylinc.com/micro-structures-power-distribution-board-model-railroad-electrical-accessory-4805

I use Menards three way power adapter and just plug it into the power distribution board.  Then wire from the board to plug adapter and plug it into the building.   I have been able to power more than 8 building this way on one power adapter.

Thank you for all of the suggestions.  I went with a circuit designed by Gunrunnerjohn.  After building it this evening with a breadboard I had on hand; I tested it and received satisfactory results. 

I am looking to do the same thing.

Can you post a link to the circuit designed by Guns?

Here are some ideas from Gunrunner...

https://ogrforum.com/t...-low-power-dc-supply

BWRR posted:

I am looking to do the same thing.

Can you post a link to the circuit designed by Guns?

Here is the circuit I'm using for my project.

What size male barrel plug will the Menards buildings accept?  Since it is hard to gain access to the wires on the inside of one of the structures, I think I'm better off just running my circuit to a male barrel plug.

The plug should be 5.5 X 2.1 mm.

I can't see the circuit...

cjack posted:

The plug should be 5.5 X 2.1 mm.

Thank You.

cjack posted:

I can't see the circuit...

That is odd.  Maybe GunrunnerJohn will attach the image of the circuit he sent me.

I hope so, that is exactly what I was hoping for

This one? Good for about 100 ma.

Lets try this again.  Yes the circuit i used is basically the same one above with the exception of the inductor. Hopefully you can see the image this time.

Lionel16 posted:

Lets try this again.  Yes the circuit i used is basically the same one above with the exception of the inductor. Hopefully you can see the image this time.

 

Yes, the inductor is inserted as isolation for layouts that run DCS. And a 7805 will do up to one amp with a heatsink.

I'd limit the current with the TO-92 part to more like 30ma, if you need more current, consider the TO220 regulator.  You'll need a lot more filter capacitance to do anything close to 1A with the larger regulator.  For a half-wave supply with 1A, I'd be looking at around 4700uf to start.