Reliable field-effect transistor timer circuit

Claim 1

A reliable timer circuit for connection to a source of direct current voltage, including: charge storage means and impedance means connected in a first series circuit to said direct current voltage source to cause a current flow and to in turn cause a charge to be stored in said charge storage means; depletion mode field-effect transistor means having a drain connection, a source connection, and a gate connection with said drain and source connections coupled in a second series circuit; said gate connection connected to said impedance means; said second series circuit further including second impedance means with said second series circuit connected to said direct current voltage source; said field-effect transistor drain and source connections forming an output circuit for said timer circuit; and switch means including connection means connected to said charge storage means with said switch means being conductive to discharge said charge storage means to bias said field-effect transistor means to a non-conductive state for a fixed interval of time; said non-conductive state of said field-effect transistor means providing said output circuit with an output voltage for said fixed interval of time.