We introduce the use of a pulse transformer as an improvement in the drive circuit of the ‘‘hairpin looppop’’sign for a pulsed molecular‐beam source. The virtue of this device is that it can produce the high currents necessary to drive the hairpin at low voltage. In addition, it minimizes theI2Rpower loss of former designs while allowing for proper impedance matching of the leads to the power supply, thus lowering the voltage requirements necessary to drive the circuit.