Fish pond aerator accidental failure alarm

The following is an aerator alarm designed by the author for fish ponds. It can monitor and alarm for several situations such as power outage, motor burnout, lack of tung, overload operation, motor and water wheel decoupling and idling, and prompt the user to check. This device is very energy-saving, can work continuously for a long time, and has high reliability.

See the attached diagram for the circuit diagram. A and B are two phases of the three-phase power of the aerator motor. T1 and T2 are two current detection coils wound outside. When the power is normally supplied, T1 and T2 supply power to the rectifier filter circuit composed of D1, D7, C1, and C4. A certain voltage can be maintained on the filter capacitor. R1 and R2 are two potentiometers. R1 performs alarm control for phase loss, overload, partial short circuit, and motor burnout. When working normally, the potential at the contact position of R1 is slightly lower than the flip voltage of IC1. IC1 outputs a high level and IC3 outputs a low level. The potential of the R2 potentiometer contact is slightly higher than the flip voltage of IC2.

The output is also low level. When overload or partial short circuit occurs and there is no phase loss, the output voltage of C1 filter increases and IC1 flips. The alarm is powered and locked, and D7 lights up permanently.

When the motor is running with a phase loss, if the phase is not the one that is missing, the total current increases, the C1 filter voltage rises, and IC1 flips to trigger the alarm circuit. If the phase is the one that is missing, the C1 capacitor voltage is 0V. It2 flips to output the trigger level to the alarm part, and an alarm is issued. In the case of motor burnout, the C1 capacitor will lose power or have a high voltage. Similarly, ICI or IC2 will flip to trigger the alarm circuit. In actual use, this fault has already shown one of the above phenomena before it occurs. This situation rarely occurs.

In addition to the above situations, R2 also alarms for the aerator's off-axis light load and power outage. This is the most likely situation for accidents in inland ponds. Under normal circumstances, adjust R2 to make the IC2 input voltage slightly higher than the IC2 flip voltage. When the off-axis situation occurs, the load is greatly reduced. The C1 filter voltage drops. The IC2 input is lower than the trigger voltage, IC2 flips immediately, and D5 issues a permanent alarm trigger and self-locks; in the case of a power outage, the IC2 input changes from a high level to a low level, which also causes the output to alarm.

N1, N2, and N3 are three push button switches.

Each time you turn on the aerator, press N1, N2, and N3 to check whether the alarm part is alarming, and perform a simple safety check on the circuit to determine whether each part is normal. IC5 and IC6 are two monostable triggers. When an alarm occurs, they can quickly inform the user of the fault type and eliminate it in time. If it cannot be reset normally, press the N4 button to reset the two triggers of CC4013.

Power source E is a 6V small battery. When working normally, D7 can provide several milliamperes of current to the circuit to supplement the static current consumption of the circuit. IC1~IC3 is a six-inverter CC4069, IC5 and IC6 are a dual D flip-flop CC4013, and the D terminal is connected to the positive pole of the power supply.

R and S are grounded. 2.8kW motor T1 has 250 turns and T2 has 600 turns.