Various examples are directed to analog vacuum tube emulator circuits. In various examples, a vacuum tube emulator circuit may comprise a first circuit and a second circuit. The first circuit may be effective to receive, a first voltage, a second voltage, and a third voltage. The first circuit may be effective to develop, at an input of the first circuit, a first current based on the first voltage, the second voltage, and the third voltage. The first circuit may output the first current to an output node. The second circuit may be effective to receive the first voltage, the second voltage, and the third voltage. The second circuit may be effective to develop, at an input of the second circuit, a second current based on the first voltage, the second voltage, and the third voltage. The second circuit may output the second current to the output node.

An LED tube lamp includes a glass tube, two end caps, a power supply, and an LED light strip. The glass tube includes a main body region, two rear end regions, and two transition regions connecting the main body region and the rear end regions. The end cap is disposed at one end of the glass tube and the power supply is provided inside the end cap. The LED light strip is disposed inside the glass tube and has LED light sources disposed thereon. The LED light strip includes a bendable circuit sheet mounted on inner surface of the glass tube. The bendable circuit sheet of the LED light strip is formed with a freely extending end portion at one end, and the freely extending end portion is electrically connected to the power supply. The glass tube and the end cap are secured by a hot melt adhesive.

In various embodiments, a light-emitting apparatus is disclosed. In one example, the light-emitting apparatus comprises a substrate, an LED string mounted on the substrate, in which LED string a plurality of LEDs are connected in series, a power supply path connected in series to the LED string, and a plurality of protection elements, each protection element having a first node commonly connected to the power supply path and a second node connected between a pair of the LEDs in the series, wherein the protection elements include capacitors or zener diodes, and an AC impedance of each protection element is smaller than an impedance between the pair of LEDs and a case ground.