Alarm relay protection refrigerator
The tripping of the protection relay of a domestic refrigerator occurs, as a rule, when fault or compressor. or starting part of the relay. Delay positives, due to the inertia of the thermocouples at a maximum current of 6 And can reach 2...2.5 s. Multiple overloads arising from unnoticed time instability of the refrigerator can lead to damage to the power components from the internal wiring to the compressor. We offer our readers a simple device will beep when each emergency opening of the food chain.
Diagram of the device shown in Fig. 1. It is a generator of AF for unijunction transistor VT1, fed from a stabilized power node R1VD1VD2C1 parallel-connected normally closed contacts K1.1 thermal overload relay (in this case, type P3). When an emergency opening on the generator receives a supply voltage, and it beeps continuously with a frequency of about 1.5 kHz.
Correctly assembled device does not require establishing. The tone of the sound signal you can change the selection of the resistor R2. When switches are connected to relays A1 you need to remove the cover the last and making the necessary connections, skip feed the wires through the slit in the housing.
Author: D. Pankratiev, Tashkent, Uzbekistan