Ritter Dental Chairs  X-100, Renaissance & Elite Models J

General Information

All Procedures for this Chair have been taken from the original Ritter Service Manual and have been edited. For more detailed information refer to the original Ritter Service Manual



The following Ritter Dental Chairs All had the  switch configuration shown below.  The far left  is the base trim switch and the middle left is the back trim, operate/exit switch.  On the right of the headrest is the  headrest locking  switch.


The early model J had a Gearmaster motor which operated the base up-and-down functions. These early motors had internal limit switches and for this reason the schematic diagrams are different. Make sure you know which base motor is on your chair. The Gearmaster motor has no replacement or replacement parts.


Later versions of the model J came equipped with Hanning base motors. These motors used external limit switches therefore the schematic diagrams are different from the early versions. Make sure you know which base motor is in your chair. These Hanning base motors are readily available.

The Ritter Dental Model J chair had three different types of PC boards mounted on it during its evolution. The latest and most widely used was the board shown on the right. This was a non programmable printed circuit board that was located under the toe of the chair. It consisted of four large relays, a transformer and various other components. This board provided low voltage to both the operating and limit switches as well as line voltage to the motors.

The second PC board was also mounted on later Model J chair's however not as widely used. This was the programmable printed circuit board and was located in the same position as the non programmable, in the toe of the chair. It is virtually identical except for the four protruding pots which stuck out beyond the case for easy access these pots were used for programming the chair to stop at a specific point.

The third PC boards came in a programmable and non programmable version. This board was located in the base of the chair. And because of the plumbing involved is sometimes hard to get to. This printed circuit board was all solid-state and had a terminal block on each side for the connection of wires. One side consisted of the line voltage for the operation of the motors the other side was low voltage to the operating and limit switches.