Temperature controlled timer

• US 4,378,486 A
• Filed: 12/29/1980
• Issued: 03/29/1983
• Est. Priority Date: 04/24/1980
• Status: Expired due to Term

• Current Assignee: Mccaine Electric, Ltd. (Bird Construction Incorporated)
• Original Assignee: Conserver Group, Inc.
• Inventors: Waldman, David, Yunik, Maurice
• Primary Examiner(s): PASCHALL, MARK H
• Application Number:
  US06/220,688
• Time in Patent Office: 820 Days
• Field of Search: 219/492, 219/202, 219/203, 219/491, 219/493, 219/497, 219/508, 219/509, 368/110, 368/111, 368/113, 165/12, 236/46 R, 236/46 A, 236/46 C, 236/91 C
• US Class Current: 219/492
• CPC Class Codes: G04G 15/00 Time-pieces comprising means to be operated at preselected times or after preselected time intervals G04G11/00, G04G13/00 take precedence; electronic timers G04F1/005; pulse delay circuits H03K5/13; electronic time-delay switches H03K17/28; electronic time-programme switches which automatically terminate their operation after the programme is completed H03K17/296

Abstract

A temperature controlled timer useful for controlling the application of power to apparatus such as automobile block heaters or the like. In one embodiment the time of application of power prior to a shut off time is decreased with increasing ambient temperature. In another embodiment the duty cycle of cyclically applied power is changed so that the power on period becomes shorter and the power off period becomes longer with increasing ambient temperature. Significant conservation of power results.

Claims

1. A temperature controlled timer comprising:

(a) a clock having a settable alarm time output adapted to provide a signal pulse having a leading edge at said set time,

(b) a first interval timer connected in a circuit path to said alarm output adapted to begin timing a first interval of time upon detection of said leading edge,

(c) a temperature sensor connected to the interval timer for controlling the duration of said first interval of time with temperature,

(d) a second interval timer connected in a circuit path to the first interval timer adapted to begin timing a second interval of time following the end of the first interval of time,

(e) manual control means for controlling the duration of the second interval of time, and

(f) an output circuit for generating a power control signal during the second interval of time,

(g) the temperature sensor being adapted to generate a signal to progressively and continuously increase the duration of the first interval of time with increase in temperature whereby the second interval of time is reduced to zero at a predetermined temperature.

2. A temperature controlled timer comprising:

(a) a clock having means to provide an output signal having a leading edge at a predetermined time,

(b) first differentiating means for receiving the output pulse and for differentiating it,

(c) first timer means having a trigger input for receiving the differentiated signal, and a timing signal input,

(d) means for sensing the ambient temperature for generating a voltage dependent on the ambient temperature and applying it to a timing signal input of the first timer, for establishing the duration of the first timing output pulse,

(e) second differentiating means for receiving the first timing output pulse and differentiating it,

(f) second timer means for having a trigger input for receiving the differentiated signal from the second differentiating means and for providing a second timed output pulse having a leading edge at the time of reception of the differentiated signal at its trigger input,

(g) a manually settable timing circuit having means for providing a voltage related to the desired duration time for the second timed output pulse,

and an output lead for carrying the output pulse, for connecting to an external switch operable by the second timed output pulse.

3. A temperature controlled timer comprising:

(a) a clock having means to provide an output signal having a pulse edge at a predetermined time,

(b) a first interval timer connected in a circuit path to said alarm output adapted to begin timing a first interval of time upon detection of said pulse edge,

(c) a temperature sensor connected to the interval timer for controlling the duration of the first interval of time with temperature,

(d) a second timer connected in circuit path to the first interval timer adapted to begin timing a second interval of time following the end of the first interval of time,

(e) manual control means for controlling the duration of the second interval of time, and

(f) an output circuit for generating a power controlling signal during the second interval of time.

4. A temperature controlled timer as defined in claim 3, in which the clock is adapted to cycle the application of said power on and off for predetermined periods of time, and including circuit means adapted to reduce the on portion and increase the off portion in each cycle with increase in ambient temperature.

5. A temperature controlled timer as defined in claim 4, including means for controlling the cycling of said power on and off to about a 50% duty cycle in the event the ambient temperature is at or below a predetermined lower temperature.

6. A temperature controlled timer as defined in claim 3, in which the second interval of time controlled by the second timer is defined by the shut-off time of the timer.

7. A temperature controlled timer comprising a first flip flop for generating a first pulse control signal having a predetermined duty cycle, ambient temperature sensing means for providing a voltage to the flip flop which is related to the ambient temperature, first means for controlling the duty cycle of the control signal in response to said voltage to increase the on time and decrease the off time with increase in ambient temperature, means for applying the first control signal to a comparator circuit, means for generating a predetermined potential when said voltage reaches a level upon the ambient temperature rising to a predetermined temperature and for applying said potential to the comparator circuit, means in the comparator circuit for providing an output control signal in synchronism with the pulse control signal, and for inhibiting the provision of the output control signal upon reception of the predetermined potential, and a second flip flop operated in synchronism but with opposite polarity pulses as the first flip flop and adapted to generate a second pulse control signal having said predetermined duty cycle but of opposite polarity, and being adapted to receive said voltage related to the ambient temperature, second means for controlling the duty cycle of the second control signal in response to said voltage, whereby the second control signal is adapted to control the on or off state of a second switch, means for applying the second control signal to a second comparator circuit with said predetermined potential, and means in the comparator circuit for providing a second output control signal in synchronism with the pulse control signal and for inhibiting the provision of the output control signal upon reception of the predetermined potential.

8. A temperature controlled timer comprising a first flip flop for generating a first pulse control signal having a predetermined duty cycle, ambient temperature sensing means for providing a voltage to the flip flop which is related to the ambient temperature, first means for controlling the duty cycle of the control signal in response to said voltage to increase the on time and decrease the off time with increase in ambient temperature, means for applying the first control signal to a comparator circuit, means for generating a predetermined potential when said voltage reaches a level upon the ambient temperature rising to a predetermined temperature and for applying said potential to the comparator circuit, means in the comparator circuit for providing an output control signal in synchronism with the pulse control signal, and for inhibiting the provision of the output control signal upon reception of the predetermined potential, a second flip flop operated in synchronism but with opposite polarity pulses as the first flip flop and adapted to generate a second pulse control signal having said predetermined duty cycle but of opposite polarity, and adapted to receive said voltage related to the ambient temperature, second means for controlling the duty cycle of the said voltage, means for applying a 50% duty cycle signal to the comparator circuit, and means for adapting both comparator circuits to inhibit generation of output control signals having duty cycles in excess of 50%.

9. A temperature controlled timer as defined in claim 8 including clock means having an output signal for driving said flip flops with a 50% duty cycles, in which each comparator circuit is comprised of a 3 input NAND gate, one input of each said NAND gate being connected to the output of the clock means, a second input of each NAND gate being connected to the output of a corresponding flip flop, and the third input of each NAND gate being connected to the output of said means for generating said predetermined potential.