Write-erase circuits for rotating head digital magnetic recorders

Claim 2

For use in a rotating head signal recorder: an improved write-erase apparatus including in combination: a rotating transformer having a stationary center-tapped primary winding, and a rotatable center-tapped secondary winding magnetic coupled to said center-tapped primary winding, a center-tapped recording coil for a recording head having its opposite ends respectively connected to ends of said secondary winding and mounted for rotation therewith, and an erase coil element electrically interconnected between the center taps of said secondary winding and said recording coil.

Claim 3

The apparatus set forth in claim 1 further including an erase gap and a write gap, the erase gap being upstream with respect to a record medium to be recorded from said write gap, and being magnetically coupled to said erase coil and said write gap being magnetically coupled to said write coil.

Claim 4

The apparatus set forth in claim 1 further including an isolating diode electrically interposed respectively between ends of said secondary winding and said write coil.

Claim 5

The apparatus set forth in claim 3 further including a constant current source, first and second switching transistors having one end connected to said constant current source, and the second end respectively connected to the opposite ends of said center-tapped primary winding, and said constant current source being connected to the center tap of said primary winding.

Claim 6

A circuit for providing erase while record functions in a rotating head transformer coupled signal recorder, the improvement including in combination: a rotatable element for use in a digital signal magnetic recorder, a secondary winding on said rotatable element having a first and second end and a center-tap connection, a write gap on said rotating element, a center-tapped recording coil having first and second ends and a center-tap connection magnetically coupled to said write gap, an erase gap, an erase coil magnetically coupled to said erase gap having first and second ends, first end of secondary winding and of said write coil being electrically connected together, the secondary ends of said primary end said write coil being electrically connected together, and the erase coil being electrically connected between said center taps.

Claim 7

A circuit for providing erase while record functions in a rotating head transformer coupled signal recorder, the improvement including in combination: a rotatable element for use in a digital signal magnetic recorder, a secondary winding on said rotatable element having a first and second end and a center-tap connection, a write gap on said rotating element, a center-tapped recording coil having first and second ends and a center-tap connection magnetically coupled to said write gap, an erase gap, an erase coil magnetically coupled to said erase gap having first and second ends, first end of secondary winding and of said write coil being electrically connected together, the secondary ends of said primary end said write coil being electrically connected together, and the erase coil being electrically connected between said center taps.

Claim 8

The circuit set forth in claim 5 further including unidirectional current conducting means electrically interposed between the first ends and said second ends and poled to conduct current in opposite directions through said recording coil such that said erase coil always receives the same direction electrical current between said secondary winding center-tap connection and said center-tap connection of said recording coil.

Claim 9

The apparatus set forth in claim 6 further including a stationary primary winding disposed in magnetic coupling relationship to said secondary winding and having a first and second end and a center-tap connection.

Claim 10

Circuit set forth in claim 7 further including first and second switching transistors, including differential control signal receiving means, and having a first connection to said first and second ends of said primary winding and having a second connection, which is common, and a constant current source connected between the common connection and said center-tap connection of said primary winding and a control connection to said constant current source.