Circuit for controlling operation of a load after a predetermined time delay

A circuit for controlling operation of an electrical load, the circuit comprising:

• a first power supply for supplying a first supply voltage;
• a trigger capacitor;
• a switch connected between the first power supply and the trigger capacitor, the switch closing to cause the trigger capacitor to be charged in response to a condition requiring operation of the electrical load;
• a trigger charge controller for controlling a delay time required to charge the trigger capacitor;
• a DIAC connected to the trigger capacitor, the DIAC generating a first trigger signal when the trigger capacitor is charged to a threshold level;
• a silicon controlled rectifier connected to the DIAC, the silicon controlled rectifier generating a second trigger signal in response to the first trigger signal;
• a first TRIAC connected to the silicon controlled rectifier, the first TRIAC conducting to supply the electrical load with a voltage substantially equal to the first supply voltage in response to the second trigger signal;
• a second power supply for supplying a second supply voltage;
• an opto-TRIAC connected to the silicon controlled rectifier the opto-TRIAC conducting to supply a third trigger signal in response to the second trigger signal;
• and
• a second TRIAC connected to the opto-TRIAC the second TRIAC conducting to supply a second electrical load with a substantially equal to the second supply voltage in response to the third trigger signal.

A detection system comprising:

• a storage element for storing a fluid, the fluid flowing in the storage element in response to a predetermined condition;
• a first electrical power supply for generating a first supply voltage;
• a threshold capacitor;
• detection means for causing the threshold capacitor to be charged by the first electrical power supply in response to fluid flow in the storage element;
• time control means for ajdustably controlling a delay time required to charge the threshold capacitor;
• a first trigger element for generating a first trigger signal when the threshold capacitor is charged to a threshold level;
• a second trigger element for generating a second trigger signal in response to the first trigger signal;
• a first switch for causing a fist electrical load to receive a first voltage substantially equal to the first supply voltage in response to the second trigger signal;
• a second electrical power supply for generating a second supply voltages;
• a third trigger element for generating a third trigger signal in response to the second trigger signal;
• and
• a second switch for causing a second electrical load to receive a second voltage substantially equal to the second supply voltage in response to the third trigger signal.

A method for controlling the operation of an electrical load, comprising the steps of:

• detecting a condition requiring operation of the electrical load;
• providing a first supply voltage to a capacitor to charge the capacitor to a threshold level over an adjustable time period;
• generating a first trigger circuit when the capacitor is charged to the threshold level;
• generating a second trigger signal in response to the first trigger signal;
• supplying a first voltage substantially equal to the first supply voltage to the electrical load in response to the second trigger signal;
• generating a third trigger signal in response to the second trigger signal;
• and
• supplying a second voltage substantially equal to second supply voltage to a second electrical load in response to the third trigger signal.