Most HF welders will have some sort of control panel for the operator. This is a list common controls and some explanations of what they do, which is ideal for people new to the operation of HF welders and could even be used as part of operator training.

ISOLATING SWITCH : Generally at point of power entry to the machine. This switch totally isolates the machine.

HV OR HT SWITCH : This switch allows the press to be cycled and die seating checked without HF power.

HOLD CYCLE WELD SWITCH : (Where fitted) Similar to HV switch, but the HV can be switched on and off without the press opening. The weld timer re-sets each time it is operated.

PRE-WELD OR SQUEEZE TIMER : This timer is initiated when the start buttons are pressed. It should be set to about 5 seconds initially and reduced to give about .5 to 1 second squeeze time before High Frequency power is initiated. When welding thick plastic or when thick foam or filling has to be compressed a longer pre-weld time is necessary to expel trapped air under the die.

Air gaps can lead to arcing and if a heated platen is supplied heat can transfer to the plastic thus preheating the weld.

PRE-WELD PRESSURE SWITCH : This control is not normally accessible, but where fitted can also give a pre-weld delay as air pressure has to build up before it switches on HF.

WELD TIMER : Weld time vary from 1 second for thin material to 8 or even 10 seconds for thick foam filled materials.

Two layers of .015" (.35mm) sheeting as used on a book cover with tear seal would normally weld in 2-3 seconds.

COOL OR DWELL TIMER : This timer allows a cool period after the weld for the heat from the plastic interfaces to dissipate to the adjacent sheeting and the die.

These times can be from almost zero on thin materials to 1 second for book binder covers, to 10 seconds on a thick lay up, as in automotive trim panels where a lot of heat is stored in the backing material.

DELAY TIMER : On automatic machines this time delay allows loading to be carried out before automatic re-initiation.

STOP, RESET BUTTON : Sometimes on large machines there are more than one of these switches, and on special applications such as the overlapper tier tray type, they lock off the circuit and have to be reset by turning and pulling.

This switch stops the machine and also resets the arc suppressor on most types.

CLICK OR CUT SWITCH : On click welders this switch stops the high pressure from being applied and the die will weld but not cut.

PLATEN HEAT : On machines fitted with heated platens this switch can turn them off. 

COUNTER : This device counts only completed welds.

ARC LAMP : Indicates that a flash has occurred on the plastic being welded.

FILAMENT LAMP : When main power is switch on this lamp will glow. If the blower is not working or blocked, this lamp will not glow.

HEAT OR POWER LAMP : This lamp indicates that high voltage contactors have closed and the HF generator is applying power to the load.