Handy Calculators
Here's a handy list of calculators and resistors selectors from our friends over at CEPD.
Resistor Calculators
There is a 1% resistor finder, resistor divider, resistors in parallel
and RC time constant calculator found in the Resistor Calculators.
Microstrip Calculators
There are microstrip impedance and differential impedance used for USB
traces found in the microstrip
calculators.
Transmission Calculators
There are line of sight VHF, power conversion and VHF signal loss found
in the transmission
calculators.
Time Conversion Calculators
There are POSIX, ISO8601, Windows Time, Julian Date, GMT, Javascript
time formats that can be found in the time conversion
calculators.
Splitter and Attenuator Calculators
Find resistor values for Y splitter, T attenuator or Pi attenuator that
can be found in the splitter
and attenuator calculators.
Power Conversion Calculator
Conver voltage, dBm, dBu, dBV, or power to another form for a given
impedance and waveform type in the power
conversion calculator.
ASCII Character Chart
ASCII
Character Chart that shows the symbols, hex values, octal
values, decimal values, binary value and description of the character.
EIA232 Reference Chart
EIA232 Reference
Chart that shows the pinout and signal names for DB25, DE9,
and RJ45 connectors.
1st Order Filter Calculators
1st Order
Filter Design for lowpass and highpass filters. The
calculators create analog component values, analog and digital filter
coeffiecients.
2nd Order Filter Calculators
2nd Order Filter
Design
for lowpass, highpass, bandpass and bandstop filters. The calculators
create analog component values, analog and digital filter
coeffiecients.
Here is a great LED series/parallel array wizzard. Also draws schematic for you:
http://led.linear1.org/led.wiz
Erroneous link. Try this one: http://www.circuitpeople.com/Blog/PanelsInPcbManufacturing.aspx
There isn't a category on this page for it, but here's a calculator (see the bottom of the page) for panelizing PCBs for manufacturing:
http://www.circuitpeople.com/www.circuitpeople.com/Blog/PanelsInPcbManufacturing.aspx
If you're planning on making more than a few PCBs, it can be a great money saver to consider how the boards can be arranged to most efficiently use the available space. The amount of panel material wasted is a big driver of cost.