15. SwitchesSwitches
➢ Single Throw, Single Pole (STSP)
➢ Double Throw, Single Pole (DTSP)
➢ Single Throw, Double Pole (STDP)
➢ Double Throw, Double Pole (DTDP)
➢ Throw == Terminal
STDP DTDP
27. Transistors vs. RelaysTransistors vs. Relays
TransistorTransistor RelayRelay
Long-term reliabilityLong-term reliability ExcellentExcellent LimitedLimited
Configurable for DP and/or DT switchingConfigurable for DP and/or DT switching NoNo YesYes
Ability to switch large currentsAbility to switch large currents LimitedLimited GoodGood
Able to switch ACAble to switch AC Usually notUsually not YesYes
Can be triggered by ACCan be triggered by AC Usually notUsually not OptionalOptional
Suitability for miniaturizationSuitability for miniaturization ExcellentExcellent Very limitedVery limited
Sensitive to heatSensitive to heat HighHigh ModerateModerate
Ability to switch at high speedAbility to switch at high speed ExcellentExcellent LimitedLimited
Price advantage for low-voltage low-currentPrice advantage for low-voltage low-current YesYes NoNo
Price advantage for high-voltage high-currentPrice advantage for high-voltage high-current NoNo YesYes
Current leakage when “off”Current leakage when “off” YesYes NoNo