The following is a series of speakers delay relay useful as a delaying the speakers. The purpose of this delay circuit is as a deterrent to prevent pounding of the very first amplifier is turned on.
This delay circuit has the advantage that is: if there konsleting, relationship with the speaker amplifier circuit will be immediately cut off, so that the speaker is safe from fire. waiting time or delay time is about 5 seconds, and can be altered by changing the condenser C2 with elco smaller value. The time needed to re-open relay if the current cut off about 0.5 seconds.
About Relay Contacts
A relay is an electrically operated switch. Electric current through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts. The coil current can be on or off so relays have two switch positions
A simple electromagnetic relay, such as the one taken from a car in the first picture, is an adaptation of an electromagnet. It consists of a coil of wire surrounding a soft iron core, an iron yoke, which provides a low reluctance path for magnetic flux, a movable iron armature, and a set, or sets, of contacts; two in the relay pictured. The armature is hinged to the yoke and mechanically linked to a moving contact or contacts. It is held in place by a spring so that when the relay is de-energised there is an air gap in the magnetic circuit. In this condition, one of the two sets of contacts in the relay pictured is closed, and the other set is open. Other relays may have more or fewer sets of contacts depending on their function. The relay in the picture also has a wire connecting the armature to the yoke. This ensures continuity of the circuit between the moving contacts on the armature, and the circuit track on the Printed Circuit Board (PCB) via the yoke, which is soldered to the PCB.