... ; 2. Frequency-sweep zero voltage start, high success rate, no shock;3. Automatic resistance adjustment, permanent power output, 10-20% ... rate; 7. Wholly digital design, strong in anti-interference, no temperature shift when in continuous working; 8. Multi-protection ... ; 2. Frequency-sweep zero voltage start, high success rate, no shock;3. Automatic resistance adjustment, permanent power output, 10-20% ...