| Section | Critical Parts | Value/Rating | | :--- | :--- | :--- | | | Ferrite core (EE25), IRF740 MOSFET, UF4007 diodes | 1.2kV out, 30kHz | | Focus/Bias | High voltage resistor chain (10MΩ + 5MΩ trimpot) | 1W, 3kV rating | | Deflection | APEX PA94 or discrete (BF869/BF870) | +/- 100V @ 50mA | | DAC | MCP4922 (12-bit, dual) | SPI interface | | MCU | Teensy 4.0 or STM32F103 | 72MHz+ for vector speed | | Power | 6.3V AC transformer (for heater) + 24V DC supply | Galvanic isolation |
Word spread slowly. More neighbors left objects at her door: a wedding ring tarnished at the edges, a hardship badge from a factory, a dog-eared paperback of verses. Each night the CRT responded in its own idiom. With the ring it drew tidy, concentric spirals as though remembering rings of years. With the badge the beam traced tight, industrious hatches. With the book it wrote, in a delicate flurry, what might have been a line of poetry—fragments that smelled like lemon oil and cigarette smoke. Crt Clock Schematic