Abstract: The invention provides an apparatus and process to cast continuously high quality hollow round steel billets or tubes. The hollow round steel billets are produced by a compact, high production casting machine incorporating a rotating hypocycloidal mandrel for inside cooling and deformation of the solidified steel. The outside cooling is by traditional mold and spray cooling. The adjustable rolling movement of the mandrel controls the uniform heat extraction from the inner annulus as well as the deformation and deformation rate of the as-cast steel to increase the ductility. The inside of the hollow round billet so formed is substantially round and the inside surface is smooth to facilitate high quality and further processing to finished pipes in conventional high production machinery.

Abstract: A supply circuit for supplying an electrical load with a relatively constant current from a variable voltage input source, the supply circuit including a blocking oscillator including a transformer with primary and secondary windings and a switching transistor, the load terminals of the switching transistor being connected in series with the primary winding across the voltage input source, a resistor-capacitor circuit connected between the secondary winding and a control terminal of the switching transistor, a diode connected between the secondary winding and a first terminal of the electrical load, a voltage feedback connection for applying to a first load terminal of the switching transistor a portion of the secondary winding voltage, and a reference voltage source connected to the control terminal of the switching transistor.

Abstract: A circuit for supplying a constant DC voltage to an electrical load and, alternatively, a relatively constant DC current to a storage battery connected in parallel with the electrical load, the circuit including a blocking oscillator having a transformer with primary and secondary windings, a switching transistor having first and second load terminals and a control terminal, and a first resistor, the primary winding, the load terminals of the switching transistor and the first resistor being connected in series across an input voltage source, a rectifier connected in series with the electrical load across the secondary winding, a controlling transistor having first and second load terminals and a control terminal, a reference voltage element connected across the load terminals of the controlling transistor and connected to the control terminal of the switching transistor, and a Zener diode having an anode connected to the control terminal of the controlling transistor and a cathode connected to the parallel a