grid 523 and ground the diodes 505 and 506 are connected in a break down or reverse bias configuration in order to precisely regulate the voltage delivered to the grid 503 likewise the diodes 515 and 506 are connected in a break down or back bias mode to precisely regulate the voltage delivered to the grid 513 the diodes 525 and 526 are similarly connected to precisely control the voltage delivered to the grid 523 the diodes 505 506 515 516 525 526 may be for instance zener diodes the breakdown voltage values of diodes 505 506 515 516 517 and 526 are selected so that the potentials at grids 503 513 and 523 with respect to respective cathodes 504 514 and 524 are equalized referring still to fig5 one skilled in the art will appreciate therefore that there are at least three ways or options to use diodes to equalize the grid potential in the respective display digits as follows first a single diode may be connected in series with the grid second a single diode may be connected in parallel with the grid to ground third two diodes may be used a first in series with the grid and a second in parallel with the grid to ground referring still to fig5 and more particularly referring to a single digit such as for example digit 501 or 511 or 521 an example of the first way or option single diode in series with grid would be connecting diode 505 or 515 or 525 in series with terminal 507 or 517 or 527 and grid 503 or 513 or 523 in the alternative an example of the second way or option single diode connected.