Energy monitor for flash welders

• US 4,084,075 A
• Filed: 05/15/1975
• Issued: 04/11/1978
• Est. Priority Date: 05/15/1975
• Status: Expired due to Term

• Current Assignee: Wean United, Inc.
• Original Assignee: Wean United, Inc.
• Inventors: Deffenbaugh, James F.
• Primary Examiner(s): Truhe, J. V.
• Assistant Examiner(s): Shaw, Clifford C.
• Application Number:
  US05/577,688
• Time in Patent Office: 1,062 Days
• Field of Search: 219/97, 219/100, 219/108, 219/109, 219/110, 219/135, 324/141, 324/142
• US Class Current: 219/97
• CPC Class Codes: B23K 11/246 for flash welding

Abstract

Means for monitoring the energy used in flash welding operations wherein two signals are simultaneously fed to the input of a multiplier, one signal being substantially proportional to the welding current, and the other being substantially proportional to the welder transformer secondary voltage applied to the work. The output of the multiplier is fed to an integrating amplifier circuit and the output of the latter is fed to a level detector amplifier. Voltage changing means is used to change the sensing level of the level detector amplifier to in turn affect operation of indicating means to indicate the sensed level.

Claims

1. Means for monitoring the energy used in welding work pieces by use of a flash welder having welding transformer means, comprising:

a four quadrant multiplier, having two inputs,

means electrically connecting to one of the inputs of said multiplier a first signal which is substantially proportional to the instantaneous value of the total current required to make a flash weld,

means electrically connecting to the other input of said multiplier a second signal which is substantially proportional to the instantaneous value of the voltage applied across the work pieces being flash welded, said instantaneous values being derived at a substantially simultaneous time,

said multiplier multiplying the instantaneous values of said current and said voltage to produce an output which is proportional to the product of the said inputs, to thereby produce a signal which is proportional to the instantaneous values of the real and reactive power of the flash welding machine circuit from which the said two inputs are derived,

means electrically connecting the output of said multiplier to the input of an integrating circuit, the latter having an output which is substantially proportional to the energy required by the flash welding operation,

and means affected by the output of said integrating circuit to provide for modification of the flash welding operation in accordance with variation of energy required to make a satisfactory flash weld.

2. The monitoring means according to claim 1 wherein said first signal is generated by a current transformer which is responsive to the current in a source line feeding the primary of said welding transformer means.

3. The monitoring means according to claim 2 wherein a resistor is connected across the output of said current transformer to transform the current signal to a voltage signal.

4. The monitoring means according to claim 1 wherein said first signal is generated by a Hall effect device which is responsive to the welding current.