NE555 Pulse Frequency Generator Adjustable Duty Cycle Signal Generator Board Module Item Type:Pulse Frequency Generator Size:2.9 x 3.6cm / 1.14 x 1.42in Fixing Hole Distance:22.5 x 30.5mm / 0.89 x 1.2in Main Chip:NE555 Weight:Weight: 10 g / 0.35 oz(approx.) Input Current:>=100mA Output current: ≥15mA (5V power supply, V-PP is greater than 50%), ≥35mA (12V power supply, V-PP is greater than 50%) Output Frequency: Low Frequency: 1Hz ~ 50Hz Intermediate Frequency: 50Hz ~ 1kHz Medium And High Frequency: 1KHz ~ 10kHz High Frequency: 10 KHz ~ 200 KHz Period T = 0.7 (RA + 2RB) C RA and RB are adjustable from 0 to 10K; C=0.001UF in low frequency gear; C=0.1UF in the intermediate frequency file; Medium and high frequency file C=1UF; C=100UF in high frequency, so the frequency of the waveform can be calculated by yourself.