Thermal protection circuit

摘要

A thermal protection circuit has two electrical connection terminals for a device to be protected, and a temperature-dependent switch. The switch is provided with a temperature-dependent switching mechanism, two stationary contacts which are connected to the connection terminals, and a current transfer element, which is arranged on the switching mechanism. The current transfer element is moved by the switching mechanism and comprises two counter contacts, which are electrically connected to one another and in temperature-dependent bearing contact with the two stationary contacts. The thermal protection circuit is provided with a controllable semiconductor valve for AC voltage having two current terminals and a control input. Each of the two current terminals is connected to one of the connection terminals, and the control input is electrically connected to the counter contacts at the current transfer element via the switching mechanism at least when the temperature-dependent switch is closed.

主权项

1. A thermal protection circuit having two electrical connection terminals for connecting a device to be protected, including:
a temperature-dependent switch comprising a temperature-dependent switching mechanism, two stationary contacts which are connected to the connection terminals, and a current transfer element, said current transfer element being arranged on the switching mechanism, being moved by the switching mechanism and, comprising two counter contacts, said counter contacts being electrically connected to one another, being in temperature-dependent bearing contact with the two stationary contacts, and in this state connecting said stationary contacts electrically to one another, and including a controllable semiconductor valve for AC voltage having two current terminals and a control input, each of the two current terminals being connected to one of the two connection terminals, and the control input being electrically connected to the counter contacts at the current transfer element via the switching mechanism at least when the temperature-dependent switch is closed; wherein the temperature-dependent switching mechanism comprises a spring part, which bears the current transfer element, is electrically conductively connected to the current transfer element, and is electrically connected to the control input at least when the temperature-dependent switch is closed; wherein the temperature-dependent switch comprises a housing, which housing accommodates the switching mechanism and has a lower part as well as an upper part, said upper part comprising an inner side, with the stationary contacts being arranged on said inner side; and further wherein the spring part is a bimetallic snap-action disc supported on the lower part at least when the temperature-dependent switch is closed.