Today, a senior in the welding power supply board in the TVS tube because no attention is negative, the output voltage is almost zero, for a long time to find the reason is anti polarity welding pipe, so to find a positive and negative pole TVS label, and naming rules.

SMBJ naming rules: TVS tube model is composed of three parts: Series Name + voltage value + single / two-way symbol

1, MAJ, SMBJ, SMCJ, SMDJ, said the package: respectively, the peak pulse power of 400W, 600W, 1500W and 3000W.

2, the number of series after the name of the breakdown voltage nominal value or reverse state voltage value.

3, A represents a one-way, CA means two-way.

With a black pipe tube of the cathode, which is the same with the tantalum capacitors, and other devices with the polarity of the label on the contrary, we must note that the tantalum capacitor on negative pole power error but will explode!