Drive unit for controlling reciprocating electromagnets

A vibration welder for welding two parts, comprising:

• a first mounting holding the first part;
• a second mounting holding the second part;
• first and second electromagnets, each having first and second terminals;
• a vibration platen coupled to the first mounting and disposed between the first and second electromagnets;
• a drive unit, comprising:
• phase U drive circuitry coupled to the first terminal of the first electromagnet;
• phase V drive circuitry coupled to the first terminal of the second electromagnet;
• phase W drive circuitry coupled to the second terminals of the first and second electromagnets;
• and
• control circuitry operable to control the phase U, V, and W drive circuitry to generate a first drive signal for energizing the first electromagnet and a second drive signal for energizing the second electromagnet, the first and second drive signals alternately energizing the first and second electromagnets to reciprocate the vibration platen.