Device for selecting a diagnosing device or stitch forming device in electronic sewing machine

An electronic sewing machine comprising a power switch;

• a pattern selecting device including a plurality of pattern selecting switches;
• a function selecting device including a plurality of switches for selecting a function of a stitch forming device;
• a diagnosing device for checking operational conditions of electronic parts of the sewing machine;
• means for discriminating the actuation states of a predetermined pattern selecting switch and a predetermined function selecting switch to produce a first signal when one of said predetermined switches is switched on;
• an initiation signal generator for producing a second signal when said power switch is switched on while said predetermined pattern selecting switch is switched on;
• first gating means for producing a third signal in response to the simultaneous generation of said first and second signals;
• time lapse counting means started in response to said third signal to produce a fourth signal representing the counted time lapse, and being stopped in response to the switching on of said predetermined function selecting switch;
• means for storing a coded signal representing a predetermined reference period of time;
• means for comparing said coded signal with said fourth signal to produce a fifth signal when the lapsed time represented by said fourth signal is smaller than said reference time period;
• second gating means responsive to the simultaneous generation of said first and fifth signals and to the switching-on of said predetermined function selecting switch to produce a sixth signal for enabling said diagnosing device;
• and third gating means responsive to the simultaneous generation of said first and fifth signals to produce a seventh signal for disabling said stitch forming device.