A device for the non-invasive programming of an implantable body stimulator. The device includes a power supply and circuitry for generating and transmitting a preselected number of pulses of radio frequency energy. A push-button switch initiates the operation of the pulse-generating circuitry and the power supply is enabled only during an interval of predetermined duration following the initiating of operation of the pulse-generating circuitry. In a preferred embodiment, the power supply includes a power source, such as batteries, and a voltage regulator for establishing a substantially constant supply voltage for all power source voltages above a preselected level. The device may include circuitry for indicating the establishment of the substantially constant supply voltage as well as circuitry for preventing the transmission of any programming pulses upon a failure to establish the substantially constant supply voltage level. The transmitted pulses may be employed to alter an output parameter of any implanted body stimulator and is described with reference to an alteration in the repetition rate of an implanted cardiac pacemaker.