DE1087673B - Interlocking circuit against premature restart for a delay relay with bimetal contact and heating resistor - Google Patents

Description

To prevent damage to the cathode of heated gas discharge and transmitter tubes, it is necessary to the activation of the grid control voltage or the anode voltage only after heating has taken place the cathode. For this purpose one uses delay relays, among other things even those in which the time-determining member is a heated bi-metal that is adjustable according to an Time actuated a contact. The disadvantage of these arrangements is due to the thermal inertia of Heating resistor and bimetal, that after switching the contact this state 45 to 60 seconds preserved. As a result, it can happen with the usual circuits that if the Voltage and a restart within the above-mentioned period of time the control or anode voltage is applied to the tubes that have already cooled down.

For locking, circuits have become known that apart from the contact actuated by the bi-metal contain one or more relays. These circuits work with considerable effort or have circuit technology Disadvantages, such as B. the fact that the lock some time after switching off the Line voltage is canceled.

The subject of the invention is a circuit, all of which is connected to a delay relay with locking solving claims with the least amount of effort.

According to the invention, a bi-metal contact switches after the delay time caused by the heating resistor has elapsed, one from the mains via the bimetal break contact charged capacitor in parallel to the actuating coil of the relay, which after responding remains excited via a self-holding contact and the heating resistor of the bimetal contact from Mains switches off, whereby the capacitor and the heating resistor are temporarily switched off when the supply voltage is switched off can only be switched to the mains again after the bi-metal has cooled down.

The mode of operation of the circuit is described using three exemplary embodiments:

In the circuit of Figures 1 and 2, 1 represents the relay to which contacts 11-14 belong; 4 is the heating resistor of the bi-metal that actuates the changeover contact 5 - usually a snap contact. When the voltage 8/9 is applied, the heating resistor 4 of the bi-metal is heated and, at the same time, the capacitor 2 is charged via the rectifier 3. After the set time has elapsed, the contact flips over 5 ·. Here, the capacitor 2 is discharged onto the coil of the relay 1, whereby the relay responds. The latching of the relay is ensured by contact 11. The heating interlock circuit
against premature restart

for a delay relay
with bimetal contact and heating resistor

Applicant:

LICENTIA Patent-Verwaltungs-G.m.b.H., Frankfurt / M., Theodor-Stern-Kai 1

Alfred Philipp, Berlin-Friedenau,
has been named as the inventor

Resistance 4 is through the opener 12 from the voltage supply 9 separated. As a result, the bi-metal cools down again.

If the mains is switched off and switched on again in the critical time mentioned, then the relay 1 do not pick up, as the working position of the contact 5 prevents the capacitor 2 from charging. Only after the bimetal and the heating resistor 4 have cooled down does the changer 5 go returns to its rest position and automatically releases the lock. Heating resistor 4 and capacitor 2 are again at the voltage 8/9. After the heating-up time has elapsed, it will discharge again in the meantime charged capacitor 2 by switching the contact 5 over the relay coil. Relay 1 pulls again on and maintains contact 11.

The capacitor 2 here performs two functions. On the one hand it causes the switching on of the relay 1 without the voltage 8/9 being applied to the relay coil, on the other hand it serves to smooth the rectified alternating voltage. Contacts 13 and 14 are used to switch the connected devices.

In Fig. 3, the relay is intended for operation on AC voltage. The rectifier 3 is only used to charge the capacitor 2 and is after the discharge of the capacitor 2 via the relay coil and response of relay 1 short-circuited. The operation of the circuit is otherwise as in Fig. 1 and 2 described.

Claims (1)

Claim: Interlocking circuit against premature reactivation for a delay relay with bimetal contact and heating resistor, thereby 009 588/308 indicates that the bimetal contact (5), after the delay time caused by the heating resistor (4) has elapsed, switches a capacitor (2) charged from the mains via the bimetal break contact (5) in parallel to the actuating coil of the relay (1), which remains energized after responding via a self-holding contact (11) and disconnects the heating resistor (4) of the bi-metal contact from the mains, and that the capacitor (2) and the heating resistor (2) only after the bi-metal has cooled down again when the supply voltage is temporarily switched off connected to the grid. 1 sheet of drawings