Circuit for monitoring an open collector output circuit with a significant offset

A monitoring circuit interfacing an open collector output stage with a voltage offset, said voltage offset preventing direct interfacing with a digital input, said circuit comprising:

• an open collector circuit having a first ground;
• a first bipolar junction transistor connected to said open collector circuit, wherein said first bipolar junction has a second ground that is different from said first ground, said first and second ground creating an appreciable voltage offset therebetween when said bipolar junction transistor is interfaced with said open collector circuit;
• a second bipolar junction transistor connected to said first bipolar junction transistor in a loop configuration,
• wherein said first bipolar junction transistor provides base current drive to said second bipolar junction transistor and said second bipolar junction transistor provides base current drive to said first bipolar junction transistor.

A monitoring circuit interfacing an open collector output stage with a voltage offset, said voltage offset preventing direct interfacing with a digital input, said circuit comprising:

• an open collector circuit having a first ground;
• an npn bipolar junction transistor connected to said open collector circuit, wherein said first bipolar junction has a second ground that is different from said first ground, said first and second ground creating an appreciable voltage offset therebetween when said npn bipolar junction transistor is interfaced with said open collector circuit;
• a pnp bipolar junction transistor connected to said non bipolar junction transistor opposite of said open collector circuit, said pnp bipolar junction transistor and said npn bipolar junction transistor forming a positive feedback on a current flow within said monitoring circuit,
• wherein said npn bipolar junction transistor provides base current drive to said pnp bipolar junction transistor and said pnp bipolar junction transistor provides base current drive to said npn bipolar junction transistor.