Home Automation FAQ : HA Equipment : Creative Control Concepts/HCS-II : Kit Construction Hints : How can I tell similar parts apart?
Some parts look very similar and they don’t use obvious formats to indicate the value. Monolythic capacitors are the worst. Here is how to read their values: The values are usually indicated in pico farads of pF. The first 2 numbers indicate the value and the third is a the magnitude. For example, a 4700pf cap will usually have 472 on it. 47 and 2 zeros = 4700pF. A 0.1uF capacitor is 10000 pF. Thus it will have 104 on it. Be careful! Some capacitors have numbers on both sides (one side is usually a lot or date code of some type) Resistor networks use a similar system. A network with 472 on it is a 4.7K or 4700 Ohm network. A network with 103 is a 10K or 10000 Ohm network. LEDs have flat edges on one side to indicate the NEGATIVE lead. Polarity sensitive capacitors like electrolytic or tantalum caps use different symbols to indicate polarity. Tantalum capacitors indicate the positive lead with a + symbol. Electrolytic caps use a strip with a – symbol in it to indicate the negative lead.
Related Questions
- Home Automation FAQ : HA Equipment : Creative Control Concepts/HCS-II : Kit Construction Hints : How should I hold parts in place before soldering them?
- Home Automation FAQ : HA Equipment : Creative Control Concepts/HCS-II : Kit Construction Hints : Is there an easier way to clean flux off a board?
- Home Automation FAQ : HA Equipment : Creative Control Concepts/HCS-II : Kit Construction Hints : How do I clean the flux off my board?
