*** M E M O R U M ***

More photos...







I'll put more up on Sunday

Mark

Interesting !

It looks like you're putting DC out?

regards
Dave

Outputs:
Two 7.5V AC feeds (for feeding to the diodes that in turn go to the +5V regulator and the -5V zener diode supply circuitry)
One +16V DC feed, for feeding to one of the diodes that in turn supplies the +12V regulator.

The +16V DC supply is generated by a LM2577 based step up DC to DC converter, which in turn is supplied by two diodes and a 2200uF 16V smoothing capacitor, which gets it's supply from the two 7.5V AC feeds.

Because I am using a 50VA transformer with a 230V primary, the two 7.5V AC outputs actually produce a bit more than the specification suggests when used at my house (where the "230V" mains supply is at, or close to 240V).

Schematic will be made available, along with a parts list when I get around to it

Also when I demonstrated it at Memofest 2014, Claus asked me about the performance when operating at 230V. So as I have a mains isolating transformer with various tappings, I will see if I can set it up to give 220V and 230V outputs, I can then test my MTX PSU using these voltages.
Mark

Mark

I think more people could be interested, cause people always miss the power unit.

As mentioned at the Memofest 2014, I am interested to buy one.

I am sure more people will be interested, so you can start a production line

Around what price can you produce one of those?

All in good time

Timing and cost is directly proportional to how much use I get of a TARDIS, should one be made available

The prototype has a mains switch which glows red when on and a green "output on" LED. For the "production version", I am open to suggestions as to the colour of this LED.

How many people are interested in buying one?
If you are a "maybe", but are going to remain undecided until the cost is known, please say so.

Also, for those people who would prefer to build their own, I will post up the details once I have drawn the schematic in a eye friendly form

Mark

mmm, what colour should the LED be . . .

Difficult question, maybe 1 led is too restrictive, maybe we should have 1 LED per output voltage?
Even better, 2 LEDs per output, that flash at a frequency proportional to the voltage

It could replace my Christmas tree lights then

OK - interested in buying, depending on price

(If you want me to draw the schematic for you, send me your "drawings" and I'll KiCad them)

regards
Dave

Construction Details

First, the DC board: Diodes:
Two 1N4001 or 1N4002 or a higher voltage rating.
Capacitors:
The small blue capacitor is a 100nF ceramic multilayer type, 5mm spacing.
The large capacitor is a 2200uF 16V electrolytic.
Fuse:
PCB fuse clips, 5mm pins, suitable for a 20mm type fuse.
1A anti-surge (A/S) / time delay (T) 20mm x 5mm glass fuse

More tomorrow (sorry it's slow, I'm a bit time poor...)

Mark

Step up DC to DC converter: Inside:

Looking good Mark! Will you be posting circuit diagrams and a parts list as I'd like to make a 110v version?