The Electronic Toolbox was created by Marcus Roskosch, and it’s a MUST HAVE, if you enjoy building anything-DIY type of projects.
Taken from the description of the program, it offers the following:
• Type listings (with color coding) for Resistors including SMD types and Capacitors • Databases for Transistors and ICs • Calculating circuit values for Resistor, Capacitor, Coil, and Filter circuits • An Ohms Law calculator • • A database for common electrical Symbols • An Indices database of common electrical components • Calculation of voltage regulators with 78xx,79xx,LM317 or LM337 • NE555 circuit design • Op-amp circuit calculation • • LED / resistor calculation • Voltage divider calculation • R/L calculations • BJT calculations • Schematic Diagrams
Only $3.99 you can’t go wrong!