More photos...
I'll put more up on Sunday
Mark
Building a replacement MTX PSU
Re: Building a replacement MTX PSU - Sneak Preview
Standby alert
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
Re: Building a replacement MTX PSU - Sneak Preview
Interesting !
It looks like you're putting DC out?
regards
Dave
It looks like you're putting DC out?
regards
Dave
Re: Building a replacement MTX PSU
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
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.
Code: Select all
My replacement MTX power supply unit
Test and set-up of LM2577 based step up DC to DC converter:-
LM2577 based step up DC to DC converter
Test input 8.01V at 19.7mA. Output (no load) 16.015V
Unit constructed, test load data:-
DIN Wire Output No load
Pin. Colour Name Voltage
1. Yellow. +16V DC 16.025V DC, 6mV ripple (meter)
2. Green. 7.5VH AC 8.93V AC
3. Red. 0V
4. Black. 0V
5. White. 7.5VL AC 8.92V AC
Internal DC supply (feeds LM2577 module):- 11.45V DC, 33mV ripple (no load).
Unit constructed, test load data:-
DIN Wire Output Lamp Current Voltage
Pin. Colour Name
1. Yellow. +16V DC Two 24V 5W 360mA 15.785V DC, 28.2mV ripple (meter)
2. Green. 7.5VH AC One 12V 21W 1.37A 8.15V AC
3. Red. 0V
4. Black. 0V
5. White. 7.5VL AC One 12V 21W 1.38A 8.18V AC
Standby alert
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
Re: Building a replacement MTX PSU
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?
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?
//CLAUS - Webmaster at www.mtxworld.dk
Re: Building a replacement MTX PSU
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
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
Standby alert
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
Re: Building a replacement MTX PSU
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
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
Re: Building a replacement MTX PSU
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
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
Last edited by 1024MAK on 16 Jul 2015 17:52, edited 2 times in total.
Standby alert
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
Re: Building a replacement MTX PSU
Step up DC to DC converter:
Inside:
Standby alert
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
Re: Building a replacement MTX PSU
Standby alert
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer in Somerset later in the year
Not as many MTXs as Dave!
Re: Building a replacement MTX PSU
Looking good Mark! Will you be posting circuit diagrams and a parts list as I'd like to make a 110v version?