Description
As described in the nixie tube power supply blog: We are privileged to offer a 5v to 170v, 20mA Nixie Tube Power supply so you don’t need to build one yourself. Now you can power your Nixie tubes from a simple 5v USB charger and has a power enable pin to allow easy turn off if required. It has a 5v feed through output voltage that can also be used to power external systems like the Raspberry Pi. Check out the connection example in the video and user guide: Nixie Power Supply User Guide Rev 1
Input connector:
1. USB Type B micro connector
Output Connectors
J1 Screw Terminal
Pins:
- 170v
- 170v
J6 Screw Terminal
Pins:
- Gnd
- N_Enable (Pull Low to enable 170v supply)
- 5v supply
Additional information
| Weight | 0.0625 lbs |
|---|---|
| Dimensions | 6 × 4 × 4 in |
| Product Dimention | 38.6mm x 29mm footprint |
Hi!
I was wondering whether I can safely pull N_ENABLE low using a 3v3-tolerant pin of an ESP? N_ENABLE seems to be connected to 5V.
Thank you
Seb
Hi Seb,
Thank you for the question. The N_ENABLE pin is safe and can be pulled low by the ESP. The N_ENABLE pin is not connected to 5v, but is connected to the base of an NPN transistor (Q26) through a 1k resistor. The 100k resistor you see attached between the base of the Q26 and 5v will ensure that the nixie supply turns off when N_ENABLE is not connected. Due to the configuration, the highest voltage that will be seen at the N_ENABLE pin when unconnected is 0.7v (the Vbe of Q26). The best way to interface is to configure the ESP GPIO as an open drain output and then pull N_ENABLE low when you want to turn on the supply. You can configure the ESP GPIO as a push pull output, but then when the GPIO is high=3.3v (i.e. the nixie power supply is off), the current output from the ESP will be 3.3v-0.7v/1k = 2.6mA. The ESP will not have any issue driving this, but it won’t be the lowest current configuration. Let me know if you have any other questions.
Thanks,
Mark