JPH0469694U

JPH0469694U -

Info

Publication number: JPH0469694U
Application number: JP11246290U
Authority: JP
Priority date: 1990-10-25
Filing date: 1990-10-25
Publication date: 1992-06-19

Description

[Brief explanation of drawings]

第１図は本考案の一実施例の回路図である。１，２……送風機、３，１２，２２……オンデ
イレイリレー、４……リセツトスイツチ、１１，
２１……マグネツトスイツチ、１３，２３……セ
ツトリセツトリレー、１４，２４……圧力スイツ
チ、１５，２５……サーマルリレー。 FIG. 1 is a circuit diagram of an embodiment of the present invention. 1, 2...Blower, 3,12,22...On-delay relay, 4...Reset switch, 11,
21... Magnetic switch, 13, 23... Set reset relay, 14, 24... Pressure switch, 15, 25... Thermal relay.

Claims

[Scope of utility model registration request]

In a cooling blower start control circuit for a TV broadcasting machine equipped with two cooling blowers operated by a three-phase power supply, two magnetic switches open and close the power supply for each blower, and a three-phase power supply is supplied to each blower. 2 thermal relays that detect an open phase condition and close the contacts, 2 pressure switches that detect the wind pressure of each blower and open the contacts, and 2 contacts that open in the set state and close in the reset state. Set Reset Relay and two first on-delay relays that close the contacts when the excitation current continues for a fixed period of time longer than the startup time of each blower, and when the excitation current continues for a fixed period of time approximately equal to the startup time of each fan. a second on-delay relay that closes a contact, and each blower control circuit has a first circuit in which a contact of the set-reset relay is connected in series with an excitation coil of the magnetic switch; , a second circuit in which the contacts of the air pressure switch are connected in series to the excitation circuit of the first on-delay relay, and the contacts of the first on-delay relay and the a third circuit in which a parallel circuit with a contact point of a thermal relay is connected in series, and the first, second and third circuits of the control circuit of one blower are connected in parallel between control power supply terminals. a cooling blower, wherein at least the first and second circuits of the control circuit of the other blower are connected between the control power terminals via the contacts of the first on-delay relay. Start-up control circuit.