Abstract: In a video amplifier including a voltage gain stage and a current-amplifying output stage, feedback is applied from an output to an input of the voltage gain stage. The output stage includes a first current gain stage having a first push-pull amplifier and a second push-pull amplifier. The inputs of each of these push-pull amplifiers is connected to an output of the voltage gain stage. The output stage also includes a second current gain stage having a common-collector NPN transistor and a common-collector PNP transistor, the NPN transistor having its base terminal connected to the output of the first push-pull amplifier of the first current gain stage, and the PNP transistor having its base terminal connected to the output of the second push-pull amplifier of the first current gain stage. The output of the output stage is provided at an output terminal connected to the emitter of the NPN and PNP transistors of the second current gain stage.

Abstract: In a video amplifier including a voltage gain stage and a current-amplifying output stage, feedback is applied from an output to an input of the voltage gain stage. The output stage includes a first current gain stage having a first push-pull amplifier and a second push-pull amplifier. The inputs of each of these push-pull amplifiers is connected to an output of the voltage gain stage. The output stage also includes a second current gain stage having a common-collector NPN transistor and a common-collector PNP transistor, the NPN transistor having its base terminal connected to the output of the first push-pull amplifier of the first current gain stage, and the PNP transistor having its base terminal connected to the output of the second push-pull amplifier of the first current gain stage. The output of the output stage is provided at an output terminal connected to the emitters of the NPN and PNP transistors of the second current gain stage.

Abstract: A reusable plant protector apparatus which can be anchored to the earth comprises a polymeric sheet having a top edge, a bottom edge, and two side edges. The two side edges further comprise a plurality of matching pairs of apertures which are offset from the side edges. The matching apertures are aligned such that an aperture on one side edge bas a corresponding aperture on the other side edge when the sheet is formed into a cylinder with a side edge overlap. The plant protector apparatus also includes a stake and a plurality of flexible ties extending through the apertures and around the stake for securing the overlapping side edges and the stake to each other. The ties are tightenable to tighten the stake against the overlapping edges thereby sealing the edges and forming a flexible cylinder around the plant to be protected. The plant protector creates a sheltered climate of higher temperature and humidity around the plant.