Search found 44 matches

by Teedoubleudee
Thu Mar 30, 2017 11:25 am
Forum: Electronics
Topic: Using 7805s in parallel
Replies: 17
Views: 1676

Re: Using 7805s in parallel

TimberSurf wrote:........................Only very brave lunatics mess about inside PSU's like this one!


O.M.G. :o :o
by Teedoubleudee
Thu Mar 30, 2017 8:02 am
Forum: Electronics
Topic: Using 7805s in parallel
Replies: 17
Views: 1676

Re: Using 7805s in parallel

Yes, I wasn't really serious about that. I expect there is a 2nd and market on eBay for it. Weighs a ton though!
by Teedoubleudee
Thu Mar 30, 2017 7:27 am
Forum: Electronics
Topic: Using 7805s in parallel
Replies: 17
Views: 1676

Re: Using 7805s in parallel

Was thinking of getting the 5v 5A as this was what the Altai was capable of. If you intend to continue with this approach, it would be easier to use an LM338T instead of multiple 7805s as it provides up to 5A @5V in a single TO-220 device. However, the requirement for extensive heatsinking still ap...
by Teedoubleudee
Wed Mar 29, 2017 6:59 pm
Forum: Electronics
Topic: Using 7805s in parallel
Replies: 17
Views: 1676

Re: Using 7805s in parallel

I like it. Hope you don't mind me copying. I've ordered the psu, some fuse holders and fuses already got the rest. Thanks again.
by Teedoubleudee
Wed Mar 29, 2017 2:14 pm
Forum: Electronics
Topic: Using 7805s in parallel
Replies: 17
Views: 1676

Re: Using 7805s in parallel

Hi Timbersurf, Was thinking of getting the 5v 5A as this was what the Altai was capable of.

I like your splitter box, is that home made or available to buy (just had a look and couldn't see anything like it on eBay)? I guess I could make do with a 5x 1amp output.
by Teedoubleudee
Wed Mar 29, 2017 9:16 am
Forum: Electronics
Topic: Using 7805s in parallel
Replies: 17
Views: 1676

Re: Using 7805s in parallel

I agree it's a humungus heat sink on the back of the Altai. So decided to put it away for another day and get one of http://www.ebay.co.uk/itm/DC-5V-12V-24V-36V-48V-Universal-Regulated-Switching-Power-Supply-LED-CCTV-PSU-/151886747221?var=&hash=item235d27d655:m:mQZovYXghnw8y48gBQEuuLw
by Teedoubleudee
Tue Mar 28, 2017 7:16 pm
Forum: Electronics
Topic: Using 7805s in parallel
Replies: 17
Views: 1676

Re: Using 7805s in parallel

OK guys, thanks for your inputs. I just happened to have that Altai still in it's box doing nothing (can't even remember what I bought it for!) so thought I'll get some use out of it. Not to worry, like you say there are other options. Why 5v? Because I use a lot of microprocessors, TTL logic and se...
by Teedoubleudee
Tue Mar 28, 2017 3:33 pm
Forum: Electronics
Topic: Using 7805s in parallel
Replies: 17
Views: 1676

Using 7805s in parallel

I have got an ALTAI P001C bench power supply unit that can deliver up to 3-5 amps at 13.8volts DC. I want to drive various logic circuits around the layout at 5v DC using L7805 regulators. Because the 7805 can only deliver a max. current of 1.5 amps I was thinking of connecting 3x 7805 to the 13.8 v...
by Teedoubleudee
Mon Feb 13, 2017 1:30 pm
Forum: Electronics
Topic: Computer controlled (timed cycle) layout lighting
Replies: 23
Views: 2451

Re: Computer controlled (timed cycle) layout lighting

Hi E2E, I don't have anything concrete to show you as this is still in my head but I expect there are links available. Check out the Picaxe forum or just google for it. What I am suggesting is a very basic set up where different LEDs or sets of LEDs are connected to the outputs of a microprocessor. ...
by Teedoubleudee
Mon Feb 13, 2017 9:10 am
Forum: Electronics
Topic: Computer controlled (timed cycle) layout lighting
Replies: 23
Views: 2451

Re: Computer controlled (timed cycle) layout lighting

About 18 months ago I built a row of Metcalfe terraced houses (the ones with just the front halves to go at the back of the layout). I went to great lengths to fit out some rooms with lights and others not in a random fashion. They all come on together with the dark, via an LDR circuit. Only a few m...
by Teedoubleudee
Mon Jan 30, 2017 10:45 am
Forum: Electronics
Topic: Testing bridge rectifiers Help??
Replies: 5
Views: 762

Re: Testing bridge rectifiers Help??

A bridge rectifier is just 4 diodes connected and packaged for convenience as per the attached diagram. If you know how to test a diode you can use this diagram o test individual components.
brect.jpg
brect.jpg (10.08 KiB) Viewed 679 times
by Teedoubleudee
Mon Jan 30, 2017 10:35 am
Forum: Electronics
Topic: Raspberry Pi 3 model train application/uses
Replies: 4
Views: 640

Re: Raspberry Pi 3 model train application/uses

I have used Picaxe micro controllers (similar but cheaper than either Rasberry Pi or Arduino) to control servo motors at level crossings etc.
by Teedoubleudee
Fri Dec 30, 2016 11:40 am
Forum: Hornby - including Lima, Rivarossi, Jouef, Electrotren
Topic: E2e's 2017 4 Wheel Coach Competition Entry
Replies: 63
Views: 5374

Re: E2e's 2017 4 Wheel Coach Competition Entry

Nice project E2E. Can you tell us the eBay seller where you got those seats please?
by Teedoubleudee
Sun Nov 27, 2016 9:34 am
Forum: Electronics
Topic: VERY thin wire
Replies: 6
Views: 641

Re: VERY thin wire

Do a search on " solderable Enamelled Copper winding wire". This is the wire used for forming coils in relays and transformers etc. and can be as thin as 0.2mm. Unfortunately, because it is manufactured for this purpose it seems to only be available in reels. A video on how to solder it ca...
by Teedoubleudee
Sun Nov 20, 2016 10:15 am
Forum: Electronics
Topic: LED wiring on mimic panel
Replies: 19
Views: 2281

Re: LED wiring on mimic panel

Although slightly different from yours (I am using the seep point motors aux switch to change what LED's are display on the mimic/control panel), I have used 1KOhm resisitors on every LED connected in parallel. If you wire them up in series the last LED in the chain won't get as much power as the f...

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