In a BBW type brake device, if a slave cylinder becomes inoperable, when a master cylinder is operated for the first time, a master cut valve is opened to charge brake fluid into a reservoir of a hydraulic modulator, and since the brake fluid charged into the reservoir is increased in pressure by driving a hydraulic pump when the master cut valve is closed, wheel cylinders are operated. The boron carbide semiconductor devices produce electric current in response to incident particles, such as alpha particles, neutrons, or photons. A shaft extends through said aperture of the second axial end wall. Such a latch needle has a reduced tolerance sensitivity during manufacture.