: Uses small, often 2-inch or 3-inch, electrostatic CRTs like the DG7-6 or DH3/91 .
PS_HV --> CRT PS_HT --> CRT PS_HT --> X_Amp PS_HT --> Y_Amp
Schematics typically achieve these voltages using a high-frequency switching transformer paired with a multi-stage Cockcroft-Walton voltage multiplier. Linear regulators or dedicated zener diode strings drop these voltages down to adjustable potentiometers for manual focus and intensity tuning. Timekeeping and Microcontroller Section Crt Clock Schematic
Always place high-value resistors (1MΩ to 10MΩ) across your high-voltage filter capacitors. This ensures the circuit discharges safely after power-off.
Here's a simplified, combined schematic: : Uses small, often 2-inch or 3-inch, electrostatic
Your schematic hinges entirely on the type of CRT tube you select. Tubes generally fall into two categories: Magnetic Deflection (Television Tubes)
G1 is biased slightly negative relative to the cathode (typically -10V to -30V), allowing electrons to pass. the modulates Grid G1.
These amplifiers take the low-voltage signals from the microcontroller and convert them into the higher voltages needed to drive the CRT's deflection plates. The schematic for these amplifiers often features a using either vacuum tubes or transistors. Their core function is to provide high voltage swing (often ±50V or more) to fully move the beam across the screen. A classic simple scope design uses two EF80 pentode tubes for this purpose.
Here's a general review of a typical CRT clock schematic:
Here is how the schematic translates time into voltage.
To turn the beam on/off while moving (avoiding retrace lines), the modulates Grid G1.