Electric Brewery Build UK Version

[barneey]

Not much progress on the build since Saturday, apart from the heatsink has now arrived.



Which weighing in at 2KG`s of aluminium I hope will be big enough, or should I have bought something with more fins?.

Anyway due to the appearance of the heatsink have decided to call the controller "Beaker" ---cue sparks and smoke...

[themadhippy]

If you havn't bougth the transformers yet you could use one with dual outputs,not a center tapped version,something like http://cpc.farnell.com/camden/ctfc12-12 ... dp/TF01339

[barneey]

The two 5 volt power supplies I bought were from Ebay http://www.ebay.co.uk/itm/250732273858 its was my intention to use them for the 5 volt supply to the Volt & Amp meters but to also use the 12 volt supply of the circuit for power supplies to the "solar" pumps. Again I`m trusting my thinking / logic is OK with this idea?

If the logic / thinking is OK for the dual usage, can anyone point me in the right direction of the part to buy (variable potentiometer?) to make the 12 volt supply variable?

Cheers

[mrlard]

I use these

http://item.mobileweb.ebay.co.uk/viewit ... 8842874326

Sorry it's a mobile link as I am on my phone

[themadhippy]

mmm id be wary of using the transformer for anything other than meters after reading the warning unless i'd gone over them with a fine tooth comb.A pots not realy ideal,but something around 20 ohms,20 watt will do it. Get your soldering iron out and build a varible psu based on an LM338.3 capacitors,bridge rectifier,1 resitorr, 1 pot and a tranny-simples

[barneey]

Just been reading up on one of Kev888 old posts for his variable power supply viewtopic.php?f=6&t=44867&hilit=solar+power&start=15 mmm

[Kev888]

Its still working so far

The IC is possibly a bit overly-refined for the needs of the pumps, a pot and big transistor as a voltage-follower would have worked and probably been more robust against overload, but then the regulator IC wasn't expensive and has in-built short circuit protection - the LM338 is even cheaper (if not so suited to sub-zero temperatures out in the garage). I also agree with themadhippy that a big pot alone would work - not ideally perhaps but well enough and more simply, but the ones I could find actually cost more, so as I'm okay with basic electronics it was easy enough.

Perhaps you could put such a variable control on the output of your 12v supply if you wanted to - though looking at the specs of the supply its a bit hard to be certain of it; i'm not sure if the currant rating is for both 12v and 5v for instance - sometimes with these things its the 5v line that has the bigger current rating and the 12v one is for more subtle uses.

Cheers
kev

[barneey]

Cheers for the replies I`m going to start looking around for a few more bits for the variable 12v system.

Also keep coming up with additional ideas of what to incorporate in the overall design, so a few more holes now might be required in the control panel, turning into a little monster.

[Fil]

have you considered an old pc psu... you have a 5v and a 12v supply ready made, lots of howto make a bench/power supply on the net... im using an old pc case for my controller so its a natural choice for me.

[barneey]

The only downside to a computer PSU that I can see is mounting the thing within the case structure, I was after trying to maintain the IP65 nature of the cabinet as much as possible?

[barneey]

mmm id be wary of using the transformer for anything other than meters after reading the warning unless i'd gone over them with a fine tooth comb.A pots not realy ideal,but something around 20 ohms,20 watt will do it. Get your soldering iron out and build a varible psu based on an LM338.3 capacitors,bridge rectifier,1 resitorr, 1 pot and a tranny-simples

Got myself some power supplies sorted with the LM338 and RV24 pots the other power supplies I have will be used solely for the LED supplies.

Now to talk "Knobs" for the pots, was thinking either a either THESE or these ONES using the two different blues? or finally Transparent

[barneey]

Kal at the Electric Brewery website has given me an insite on the shared 5V supply for the Volt & Amp meters:-

EDIT Kal`s Question to Supplier and their response...............

"Kal" I've now received my replacement 3 Digital Blue LED AC 0~700V Volt Panel Meter. Thank you!

I have a question for your engineers. The input of this volt meter is:

Pin 1: AC Voltage, ~
Pin 2: NC (Not Connected)
Pin 3: AC Voltage, ~
Pin 4: Power In. GND, Negative
Pin 5: Power In. +5V DC, Positive

Pins 3 and 4 are shorted together on your printed circuit board with a copper trace. This sends one of the AC inputs to DC GND. The DC power supply I use to power this panel meter is also used by other devices such as your 3½ Digital Blue LED AC 0~50A Amp Panel Meter + Shunt, so this short causes up to 700V AC to be sent to the other devices. I would prefer not to do that.

Question:

Can I cut the copper trace between pin 3 and pin 4? Will this cause the AC inputs to "float" so that they are completely isolated from the DC GND and +5V DC power inputs?

Thank you!

"Manufacturer" Dear sir,
Thanks for your reply.
Cut connection between pin3 and pin4 to can’t make AC inputs isolated from DC GND.
And it is not suggested to test the AC current and voltage at the same time with the meters powered by the same power supply.
It may lead to burn of your meters.
Our company will develop a new type of panel meter, in which tested signal is isolated from power supply.
Best wishes

[Andy]

Isn't that response a bit ?

[barneey]

I think if I was to start again, I would question the use of the meters, they look pretty, but do I need them? or at the very least find an alternative meter product to use.

[Highlander]

Barney, If its any help this is what i've ordered from maplin for my dual solar pump power supply.
You just need to add a box and mains power adaptor. I'm planning to use a dell Laptop power supply instead of buying a plug adaptor.
If you follow the basic LM317 circuit (as per Kev's diagram or google search) you should be able to figure out wher the components go.
430 ohm resistor M430R 2
10u Cap KQ64U 2
.1u Cap AU07H 2
1u Cap AU09K 2
1n4001 Diode N72CA 4
LM317 UF27E 2
Variable resistor 4K7 FW01B 2
PCB FL17T 1
voltage display 2 http://www.ebay.co.uk/itm/170846293051? ... 1497.l2649
Enclosure
Knob FC95D 2
switch N52BW 2
Power connector E17AA 3
Plug HH60Q 3