DIY, convert led blinking into a gate

useful to clock the modular by external source, like old drum boxes and other devices with led. Need to be followed by a multiplier like 4MS scm and a gate delay to compensate the led/circuit delay.

http://www.dendrobate-magnetique.org/synth/article31/diy-ldr2gate

• ? mA +12V
• ? mA -12V
• ? mA 5V

No info about availability.