Kar relays yɛ relays a wɔde di dwuma wɔ kar mu. Saa relays yi sesa adesoa ahoɔden a ɛkorɔn na ɛwɔ shock ne vibration resistance a ɛkorɔn.
Kar ahoɔden a wɔde ma no dodow no ara yɛ 12V, na wɔtaa yɛ coil ahoɔden no sɛ ɛnyɛ 12V. Esiane battery ahoɔden a wɔde ma ne voltage a entumi nnyina nti; nneɛma a atwa yɛn ho ahyia tebea a emu yɛ den; ne pull-in voltage a ɛba fam koraa (V Ennu anaasɛ ɛne 60% VH yɛ pɛ, rated operating voltage); wɔma kwan ma coil overvoltage du 1.5VH. Coil ahoɔden a wɔde di dwuma no dɔɔso koraa, mpɛn pii no ɛyɛ 1.6–2W, na ɛde ɔhyew a ɛkɔ soro ba. Nneɛma a atwa yɛn ho ahyia ho ahwehwɛde yɛ katee koraa: wɔ engine dan mu no, ɔhyew a ɛwɔ baabi a atwa yɛn ho ahyia no yɛ -40℃kosi 125℃; wɔ mmeae afoforo no, ɛhɔ yɛ digrii -40 kosi digrii 85 . Ɛsɛ sɛ relay ahorow a wɔde di dwuma wɔ engine dan mu no gyina anhwea, nsu, nkyene, ne ngo ano; wosow ne ahodwiriw nso yɛ nea ɛhwehwɛ pii kɛse.
Control relay wɔ afã atitiriw abien: control system ne controlled system. Nea enti a control relays betumi adi dwuma a wɔde di dwuma ne sɛ, sɛ wɔde sɛnkyerɛnne pɔtee bi, te sɛ anyinam ahoɔden, magnetic, ɔhyew, anaa optical honam fam dodow bi hyɛ ne control system no mu na edu bo pɔtee bi a, controlled system no dodow a wɔahyɛ so (a wɔsan frɛ no output circuit) no betumi asesa mpofirim afi zero akɔ bo pɔtee bi, anaasɛ afi bo pɔtee bi so akɔ zero, na ɛnam so ama wɔatumi ayɛ nnwuma te sɛ control, ahobammɔ, . nsɛm a wɔde mena, ne nsɛm a wɔsakra. Su a ɛwɔ control relays mu ne sɛ wotumi de current ketewa bi di current kɛse bi so.
