WatchDog Approved Trading Robots & Brokers
4 stars based on
This application is a divisional patent application of its copending parent patent application, Ser. This invention relates to a new control unit and a new method of making the control unit, the control unit being particularly adapted to be utilized for controlling the operation of a cooking apparatus or the like. It is known to provide a temperature regulating control unit comprising a RTD temperature sensor, means for applying electrical signals to the sensor, and a microcomputer for receiving digital signals from the sensor in relation to the temperature being sensed by the sensor, the means for applying electrical signals to the sensor applying constant current to the sensor.
It is also known to provide a control unit comprising a high energy control circuit means having an output relay driver transistor, manually operated means for initiating the operation of the high energy control circuit means, microcomputer means for operating the high energy control circuit means after the manually operated means has initiated the operation thereof, and supervisory circuit means for detecting dynamic failure of the microcomputer means and disabling the high energy control circuit means if the microcomputer means is not operating in a normal mode thereof, the supervisory circuit means having means requiring the manual operation of the manually operated means before permitting power to reach the high energy control circuit means whereby the high energy circuit means is disabled unless the manual operation of the manually operated means has taken place and the microcomputer means is operating in the normal mode thereof.
For example, see Fowler U. It is a feature of this invention to provide a new temperature regulating control unit that is less costly and requires fewer and less critical components than prior known temperature regulating control units that utilize a binary options watchdog reviews ignition coils current to excite the sensor. In particular, it was found according to the teachings of this invention that an RTD temperature sensor can have a varying voltage applied thereto and such temperature sensor can be utilized to apply digital signals to a microcomputer in relation to the temperature being sensed by the sensor.
For example, one embodiment of this invention provides a temperature regulating control unit comprising an RTD temperature sensor, means for applying electrical signals to the sensor, and a microcomputer for receiving digital signals from the sensor in relation to the temperature being sensed by the sensor, the means for applying electrical signals to the sensor applying a varying voltage to the sensor.
It is binary options watchdog reviews ignition coils feature of this invention to provide a control unit having a unique supervisory circuit means for monitoring the high energy control circuit means thereof. In particular, it was found according to the teachings of this invention that a comparator of a prior known supervisory circuit means could be eliminated and that a supervisory transistor of the supervisory circuit means could be disposed in series with the output relay driver transistor of the high energy control binary options watchdog reviews ignition coils means with the requirement that the supervisory transistor must be switched on to enable the relay driver transistor.
Accordingly, it is an object of this invention to provide a new control unit having one or more of the novel features of this invention as set forth above or hereinafter shown or described.
Another object of this invention is to provide a binary options watchdog reviews ignition coils method of making such a control unit, the method of this invention having one binary options watchdog reviews ignition coils more of the novel features of this invention as set forth above or hereinafter shown or described. Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:.
While the various features of this invention are hereinafter illustrated and described as being particularly adapted to provide a control unit for controlling a domestic cooking oven or the like, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide a control unit for controlling other apparatus or appliances as desired.
Therefore, this invention is not to be limited to only the embodiment illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.
Referring now to FIG. The control unit 20 is a solid state, microcomputer based device capable of providing several advanced functions for home use, self-cleaning ovens. When used in conjunction with the appropriate temperature sensor and power interface circuitry, the control unit 20 provides the following main functions: Data entry is accomplished with the eight function keys S1-S8 in conjunction with the rotary switch The user selects a function with one of the keys S1-S8 and then enters data via the rotary switch 24, in the manner fully set forth in the aforementioned patents.
Information is displayed to the user by means of the vacuum fluorescent display Time and oven temperature information is displayed simultaneously. The display 22 is color coded for ease of identification with time information being blue-green and temperature information being red.
The control unit 20 has an electrical circuit means therein which is generally indicated by the reference numeral 25 in FIGS. The block 27 comprises the electrical power supply for the control unit 20 and is adapted to be interconnected to an external power supply 38, FIG.
The block 28 comprises a 60 hz reference generator to provide the real time reference signal utilized by the control unit 20 and the block 29 comprises a power on reset to provide a reset state for the control unit whenever insufficient voltage is available to properly power the control unit The block 31 is the user interface means of the circuitry 25 that contains the eight push buttons on keys S1-S8 and the rotary switch The block 32 comprises a microcomputer that is hereinafter referred binary options watchdog reviews ignition coils as U2 in this description and in FIG.
The block 35 comprises a free running oscillator U1 whose frequency is a nominal 2. The block 36 comprises an oven interface means that has three outputs and a software monitored input from an externally interconnected self-clean door lock mechanism 40, the outputs activating externally interconnected relays not shown which, in turn, respectively activate the oven bake element and oven broil element as well as a down draft fan if required that are schematically indicated by the external block 41 of FIG.
The two outputs of the block 36 that control the heating elements must pass current through the block 37 prior to enabling the element relays, the block 37 comprising a watchdog circuit that supplies redundant control of the heating elements by requiring a mechanical key closure prior to allowing power to reach the relays that control the heating elements in a manner hereinafter set forth.
The power supply block 27 is of conventional construction as illustrated in FIG. The -VFD supply is a source of approximately volts D. It is unregulated and supplies the vacuum fluorescent display 22 plus the volt regulator. Diodes D3 and D5 and capacitor C4 are the primary components, forming a half-wave, capacitive input circuit. The large, mfd. Sufficient energy must be stored to allow continued microcomputer operation, without reset, for at binary options watchdog reviews ignition coils 4 seconds after power is removed.
To improve this ability still further, diode D2 also couples energy from the mfd capacitor C2 in the -VR supply in the event of a power dip. This has practical value only if the relay outputs are off at the time of power interruption. The two supplies are charged from opposite phases of the incoming A. This minimizes voltage fluctuations as loads change and balances the load placed on the power transformer. Its purpose is to provide power for external D. The components comprising this circuit are diodes Binary options watchdog reviews ignition coils and D4, capacitor C1 and the external Class 2 power transformer It will provide approximately VDC when loaded with 80 ma.
This supply is developed separate of the -VFD supply to provide failure isolation and from the logic supplies which are developed from -VFD. It consists of resistors R6 and R2, transistor Q1 and zenor diode Z1. The base of transistor Q1 is tied to the junction of resistor R2 and diode Z1, which form a voltage divider producing a stable binary options watchdog reviews ignition coils The circuits being powered by this supply become the emitter resistor for transistor Q1, whose current gain provides a stable source of voltage that is 0.
Hence, a source of VDC which maintains its voltage under varying load conditions is created. It is also used as a preregulator for the -VDD supply, which powers the microcomputer U2. It consists of resistor R3, transistor Q2 and zenor diode Z2. It is especially stable due to the input source already being a regulated voltage. The 60 Hz reference generator circuit 28 provides the real time reference signal used by the microcomputer U2 to generate accurate Time of Day Clock, Timer and other functions requiring consistent real time response.
It is basically an inverting, single transistor amplifier, driven to saturation by a signal derived from the AC power line. This signal is taken directly from the Class 2 power source It is conditioned through a low binary options watchdog reviews ignition coils filter to prevent errors due to electrical noise on the AC line, before being applied to the base of transistor Q3. The filter consists of resistances R7 and R10, capacitor C5 and resistor R Transistor Q3 inverts and squares up the incoming sinusoidal waveform before applying the resulting square wave signal to pin 23 of the microcomputer U2.
Resistor R13 is merely a pull-down resistor allowing the collector of transistor Q3 to swing between 0 and -5 V. Capacitor C13's function is to decouple radiated RFI, which could upset timing accuracy if not suppressed. Since failure of this circuit would result in the microcomputer U2 losing its capability to keep accurate time, it is supervised in software.
Inhibiting this signal will result in the error code -F6- being displayed, and an audible alarm to sound, with all outputs shut down. The power on reset functional block 29 provides a single binary options watchdog reviews ignition coils that is applied to pin 49 of the microcomputer U2 which is the reset input of the microcomputer U2. Its function is to provide monitoring of the -VFD supply and to place the microcomputer U2 in a reset state whenever insufficient voltage is available to properly power the device.
It does this by driving pin number 49 high under insufficient voltage conditions, which is the reset state of this input. Resistors R1 and R5 form a voltage divider placing After power is applied to the control, the -VFD supply voltage rises at a rate dependent on the value of capacitor C4 and the characteristic impedance of the external power transformer This latching action prevents oscillation of the circuit at borderline trigger voltages.
It also provides hysterisis action which avoids resetting the microcomputer U2 until just before the -5 volt supply falls out of regulation.
Binary options watchdog reviews ignition coils delays the decision to reset from a powered state as long as possible to allow the 4 second power loss withstand capability. Resistors R9 and D23 form a level shift circuit to protect the 5 volt reset input of the microcomputer U2 from the 15 volt output swing of the op amp U1.
The resistor R4 is a pull-up resistor for the op amp U1 which assures proper logic levels and initial state of U1's output. The temperature sensing circuit 30 of this invention improves upon the prior known circuits in several ways.
For example, a ramping voltage, rather than a constant current, is used to excite the sensor This creates a less costly, yet accurate arrangement, requiring fewer and less critical components. The circuit 30 is also insensitive to power supply variations, allowing that circuitry to also be less complex.
Also, through software logic, circuit faults that could produce temperature sensing errors of a troublesome magnitude may be detected and acted upon by the microcomputer U2 of binary options watchdog reviews ignition coils invention. When used binary options watchdog reviews ignition coils a temperature controller, the circuit 30 may shut down a heat source and sound an alarm when the device's ability to control temperature accurately is jeopardized.
This is achieved without expensive power supply additions. Calibration is also performed without moving parts or potentiometers and the method is electronic. As illustrated in FIG. Pin 3 of network R18 is the terminating pin for the ladder network and pin 12 of binary options watchdog reviews ignition coils R18 is the analogue output pin. Pins of network R18 are the eight input terminals to the ladder network, with pin 4 of the network R18 being the least significant bit LSB and pin 11 of network R18 being the most significant bit Binary options watchdog reviews ignition coils.
The pattern of 1's and 0's that are applied to the inputs of the network R18 are in the form of either a binary up count or binary down count. The binary options watchdog reviews ignition coils of this action appears at the output pin 12 of the network R Starting at binarythe voltage at pin 12 of the network R18 will be equal to the voltage of the -VDD supply.
As the output pins of the microcomputer U2 count up, a positive going staircase waveform appears at pin 12 of the network R With a count ofthe voltage at the pin 12 of the network R18 is maximum. When a binary down count is applied, the sequence is reversed and the waveform at pin 12 of the network R18 becomes a negative going staircase waveform.
The output waveform of pin 12 of the network R18, 12 is conditioned by operational amplifier U1 and applied to the RTD sensor 39 through series resistors R65, R20 and R19, and returned binary options watchdog reviews ignition coils circuit common through resistor R This results in a varying voltage being applied to the sensor 39 rather than the conventional constant current excitation. The RTD censor 39 is of such construction that the electrical resistance of the sensor 39 increases as the temperature of the sensor 39 increases, giving it a positive temperature coefficient.
This resistance change is very predictable and repeatable. Because of this, the voltage across the sensor 39 is very predictable with a known current flowing through the sensor By exciting the sensor 39 with a known, accurate current, a known accurate voltage is developed across the sensor This known, accurate voltage may be interpreted, using digital techniques, into a temperature indication. The reverse is also true, and forms the principle of binary options watchdog reviews ignition coils of this circuit arrangement When a known voltage is applied, the current through the sensor 39 will be of a known amount at any given temperature.
In this case, a known proportional voltage source, is produced by the microcomputer U2 and the Custom Circuit R18, and applied to the RTD sensor