JPS5829793Y2 - Composite timer for refrigeration and air conditioners - Google Patents

Description

[Detailed description of the invention] This invention relates to a compound timer suitable for controlling the operation of refrigeration and air conditioners such as heat pumps and air conditioners. To provide an inexpensive electronic compound timer that is integrated with a malfunction prevention timer.

Conventionally, when operating the compressor of a refrigeration and air conditioner, restarting the compressor immediately after stopping the compressor does not restore the balance between high and low pressures, resulting in an extremely heavy load, and in some cases, the compressor This is considered undesirable because it causes the motor to lock up, and in order to prevent this from restarting, especially large compressors have been provided with a restart prevention timer.

On the other hand, in heat pump operation, when the compressor starts operating at a low outside temperature, the pressure on the low pressure side suddenly drops temporarily and the temperature of the low pressure side coil drops, so a coil temperature detection type icer (defrost detection device) is used. In some cases, this has the disadvantage that it mistakenly assumes that the temperature of the coil has decreased due to frost formation and enters a false defrost operation, which delays the rise in room temperature.

In order to eliminate this drawback, it has been considered to provide a timer that cancels the iser operation when the compressor starts operating.

However, providing both the restart prevention timer and the defrost malfunction prevention timer increases the price, and usually either one or both may be omitted, which has the drawbacks mentioned above. .

The present invention has been devised in view of this point, and aims to provide an electronic compound timer that can perform both of these operations with a single common timer.

The present invention will be explained in detail below with reference to the drawings.

FIG. 2 is a circuit diagram of an embodiment of the present invention.

The output Q of the timer circuit T16 is input to AND circuits A3 and A4.

The output S2 of A3 passes through a negative circuit N8 and is input to an AND circuit A5 together with a signal S5 from the thermostat, and its output S1 controls a compressor motor control relay R1.

The output S3 of the AND circuit A4 passes through the NOT circuit N9 and is inputted to the AND circuit A6 together with the signal S6 from the de-Icer.
The output S4 controls the defrost circuit control relay R2.

The output S1 of the AND circuit A5 further passes through the NOT circuit N7,
It is given to the input of the AND circuit A3 in the form of an inverted output S1,
It is also directly applied in the form of Sl to the input of the AND circuit A4.

Both outputs of S, ,S, are sent to the differentiating circuit D15. Through D14,
The output of the OR circuit 01 is applied to the trigger terminal φ that instructs the timer circuit T16 to start integration.

D14. The output of D□5 is also the RS flip-flop F
The output Q controls the output signal duration control terminal C of the timer circuit T16.

Negation circuit N8. The output of N9 is input to the OR circuit 010 via differentiating circuits DI2 and D13, and its output is applied to the reset terminal R of the timer circuit T16.

With the above circuit configuration, the differential circuits D1□ to D1. Both generate a positive output pulse when the input changes from a low level to a high level, and when a positive pulse is applied to the trigger terminal φ, the timer circuit T16 determines whether its control terminal C is at a high level or a low level. Therefore, the duration T.

Or T.

It generates an output signal of . This timer circuit T
For example, in an analog timer, the time constant of the timing circuit is switched depending on whether the control input terminal C is at a high or low level, and in a digital timer, the clock frequency is kept constant and the preset and count numbers are set. It is possible to switch the clock frequency depending on whether the control input terminal C is at a high level or a low level, or to keep the preset count constant and switch the clock frequency depending on whether the control input terminal C is at a high level or a low level.

Next, the operation of the circuit shown in FIG. 2 will be explained with reference to the timing diagram shown in FIG.

Figure 1 A to E are S1 signal, S1 signal, S2 signal, S3
signal, S4 signal is shown.

First, when the power is turned on at time to, the S1 signal becomes a high level H (that is, relay R1 is on and the compressor is on), and the output of the differentiating circuit D15 is applied to the trigger terminal φ of the timer circuit T16, and the timer circuit The output Q of the circuit T16 becomes high level.

The input of the AND circuit A4, that is, the S1 signal, and the timer circuit T1
The signals of output Q of S3 are both high level, so S3
The signal becomes high level.

This duration is determined by the timer circuit T, assuming that Sl is at a high level.
16 is at a high level, but at time t.

, the output of the differentiating circuit D15 is the RS flip-flop F.
It is also input to the set input terminal S of No. 17, and this output Q signal is set to the Mr. I level L.

Therefore, the control power C of the timer circuit T16 is at a low level, so the duration is T.

′ is selected. This time t. During the period from tl to tl, one of the inputs of the AND circuit A6 receives the S3 signal, that is, the low level, due to the action of the NOT circuit N9, so the output signal S of the AND circuit A6 is
4 is set to a low level and relay R2 is turned off, there is no possibility of accidentally entering the defrosting operation.

This T. 'The time depends on the capacity of the compressor, but is approximately 3-10 minutes.
A minute or so is sufficient.

On the other hand, at this time t.

During the period from tl to tl, the S1 signal is high and the Sl signal is low, so the output S2 signal of the AND circuit A3 is low.

The inputs of the AND circuit A5 are the S2 signal on one side and the S5 signal from the thermostat on the other, and since these are both at a high level, Sl is at a high level, so that the relay R1 is turned on and the compressor is turned on.

Next, at time t1, the output Q signal of timer circuit T16 becomes to'
When the time integration (count) ends and changes from high level to low level, the output S3 signal of AND circuit A4 also changes from high level to low level, the output of NOT circuit N9 changes from low level to high level, and the differential Circuit D13 produces a positive output pulse.

This output is inputted to the reset power R of the timer circuit T16 via the OR circuit 010 in preparation for the next integration of the timer circuit T16.

This T. ' During this time, the pressure on the low pressure side of the compressor has returned to its normal value and the temperature has also risen, so while the S3 signal is at a low level, the AND circuit A6 is activated by the S6 signal from the de-Icer.
, so relay R2 is controlled.

On the other hand, even if the timer circuit T16 output Q signal changes from high level to low level at time t1, the output S2 of AND circuit A3 is not affected because the S1 signal is already low level, and Sl is at high level, so relay R1 is On, compressor is on.

When the S5 signal from the thermostat changes from high level to low level at time t2, the S1 signal also changes from high level to low level, turning off relay R1 and turning off the compressor.

This change changes Sl from a low level to a high level via the inverting circuit N7, so a positive pulse is output to the output of the differentiating circuit D14, which is sent to the trigger terminal of the timer circuit T16 via the OR circuit 01. is added, starting its integration and causing the output Q signal to go high.

At this time, the reset terminal R of the flip-flop circuit F1□
Since a positive pulse is also input to the output Q, its output Q becomes a high level for a duration T.

is selected.

This T. During this period, the AND circuit A3 output S2 signal becomes high level, and one of the inputs of AND circuit A5 becomes low level due to the action of the NOT circuit N8, so that the S5 signal from the thermostat
Regardless of the signal, the S1 signal will be at a low level, so the relay R will be off, the compressor will be off, and the restart prevention timer will be implemented.

The time T required to prevent this restart.

It also depends on the capacity of the compressor, and is generally about 3 to 10 minutes.

Time t3, that is, period T.

When the output Q signal of the timer circuit T16 changes from high level to low level at the end of , the output S2 signal of AND circuit A3 changes from high level to low level, so the output S1 signal of AND circuit A5 is only the signal of thermostat S5. It will depend on.

At this time, the change of the S2 signal from high level to low level is
The signal is input to the reset terminal R of the timer circuit T16 via the differential circuit D2 and the OR circuit 010, in preparation for the next integration operation.

At time t4, the S1 signal changes from low level to high level due to the S5 signal etc. from the thermostat, relay R1 is turned on, and therefore the compressor is also turned on, but the operation at this time is at time t.

is the same as , so it will be omitted.

Next, let us consider a case where the compressor continues to be on and regular defrosting begins at time t1o.

Time t□. When the signal S6 from the de-icer issues a defrost command and S6 is changed from a low level to a high level, the compressor is turned on just before time tlo, so the S1 signal is at a high level, so the output S3 signal of the AND circuit A4 is at a low level. (The output Q signal of the timer circuit T16 is at a low level at time t and thereafter).

Since the NOT circuit N9 causes one input of the AND circuit A6 to be at a high level, the output signal S4 depends on the S6 signal from the de-icer.

While the S6 signal is at a high level from time tlo to tll, S
4 signal is also at a high level, relay R2 is turned on, and the four-way valve, outdoor fan motor, etc. are controlled to the operation mode necessary for the defrosting state.

When the S6 signal changes from high level to low level at time t1□, the S4 signal also changes from high level to low level, and relay R2
is turned off and released from the defrosted state, that is, the cooling cycle, and switches to normal heat pump operation, that is, the heating cycle.

As described above, in the present invention, the restart prevention timer and the defrost malfunction prevention timer are automatically selected and obtained from one timer circuit T16 according to the switching of the compressor on and off.
It has the feature that it can be constructed at low cost.

This circuit is especially suitable for a case where a thermostat or a de-iser is all electronic, and the present invention is highly practical as it protects the compressor and improves comfort.

In addition, T in Figure 1. If =To' is sufficient, the flip-flop circuit F17 can be omitted.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the operation of a circuit according to one embodiment of the present invention, and FIG. 2 is a circuit diagram of a second embodiment of the present invention. In the figure, R1 is a compressor control relay, R2 is a defrost control relay, A3 to A6 are AND circuits, N7 to N9 are negative circuits, 01o and 01□ are OR circuits, D12 to D15 are differential circuits, and T16 is a timer circuit. , F1□ are flip-flop paths.

Claims (1)

[Scope of utility model registration request] In a refrigeration air conditioner, the switching from off to on of the compressor is detected and the output is HIGH for a certain period of time (To'). I'o) first means for producing a HIGH output, and logic between the output from the first means and the inverted signal of the compressor operating state; the inverted signal of the AND output; and the output signal from the temperature sensing device; a second means for controlling the compressor drive relay according to the product signal; and a logic of the inverted signal of the AND output of the output from the first means and the compressor operating state signal and the output signal from the defroster detection device. and third means for controlling a defroster circuit relay using the product signal.