In order to meet the needs of the control loop, often require electromagnetic relay or transistor relay to accelerate or delay action, from action to constitute accelerate or delay circuit.
Circuit shown in Figure 6-23. These types of circuit is the use of a capacitor charging and discharging of the relay coil to delay the release time Ran. Figure 6-23 (a) ~ (c) is the instantaneous pull, delayed release circuit; Figure 6-23 (d) to pull delay, release delay circuit. The maximum time delay relay may be estimated by the following equation: t = 0 85R.. CX10-6 (s) where R: - the total circuit resistance, R: = R + RL, 0; R resistance, 0; foot L- relay coil resistance, N; C capacitance, pF.