Fen Logic Ltd. Electrocalc Electrocalc is a program to help with the most common electronic calculations. If you are just like me you know most electronic formulae by heart. And when using Ohms law the formula V=IxR is easily converted to R=V/I or I=V/R.
But how about Vt=Vo(1-e^(-t/(RC)))? Isolating C is a bit more difficult. Next you have to select the nearest R and C from the E12 or E24 range and then calculations start again to find the actual t or Vt with the chosen R and C values.
Electrocalc is a great help with that. You select the variable you need, fill in the others and the answer comes out.
It has formulae for:
• Ohms law
• Impedance network solver
• Charging capacitor
• Discharging capacitor
• Capacitor loaded by constant current
• RC filters
• Pi-Delta conversion
• Series RLC network
• Parallel RLC network
• LC network with internal resistance of L

As with all my GUI programs, the code consists of a small excutable but requires some big QT4 dlls to run. (See also the
bottom of this page). This is the electrocalc.exe code, there is also a zip version.
These are the QT4 dlls (4.8Mbytes) in zipped format only.

Ratio: Ratio is a program to find the optimal component choice. For example you need a voltage divider with an input/output ratio of 0.63. But which two resistor values get you closest? (The answer by the way is 330 and 560 from the E12 series or 300 and 510 from the E24 series)
Besides the most common formulae you can enter your own expression which will then be searched for an optimal solution. (Which may take a while...)
The main features:
• Select the E12, E24, E48 or E96 series to choose values from
• Select required Accuracy 5%..0.01%
• Five built-in formulae:
• A/(A*B)    (Voltage divider)
• A+B       (Series R,L or paralleL C)
• A/B        (General ratio)
• (A*B)/(A+B) (Parallel R,L or series C)
• User programmable expression

As with all my GUI programs, the code consists of a small excutable but requires some big QT4 dlls to run. (See also the
bottom of this page). This is the ratio.exe code, there is also a zip version.
These are the QT4 dlls (4.8Mbytes) in zipped format only.

PICT2ASC: PICT2ASC is a program to convert images to PadsⒸ ASC format so they can be placed on a PCB.
For example this one: comes out on a PCB like this: The main features:
• Wide range of input image formats
• User controllable threshold
• Black and white can be inverted
• Image can be scaled
• Selectable line scan width
• Selectable output layer

As with all my GUI programs, the code consists of a small excutable but requires some big QT4 dlls to run. (See also the
bottom of this page). This is the pict2asc.exe code, there is also a zip version.
These are the QT4 dlls (4.8Mbytes) in zipped format only.
This program requires additional dlls for handling all the various graphic format files.
imageformat dlls (325Kbytes) in zipped format only.

Caveat Emptor: (or in plain English: Beware!)
All these programs are free. They come with no warranty as each will tell you in their help file. If you want extra features I am willing to listen but limited in time so it may take a whil.e (Or I may plainly reject you request.) Of course throwing money in my direction might help ☺.