RFQ/BOM 0 Se connecter / Registre

Sélectionnez votre emplacement

image de l'utilisateur

As shown in the figure, the green light of the control circuit of the water dispenser is not on. Is there something wrong with the circuit diagram?

Hardware design
juillet 01, 2020 by Elliot 397

Tous les commentaires

user image

Freya Posté sur July 1, 2020

What is the power supply of 1.5v and why is it so.

0
user image

Aria Posté sur July 1, 2020

Do you want to do it, turn on the red LED2 when U4 outputs high level, and turn on the green LED1 when U4 outputs low level?

There are two errors:

1. Circuit error. The emitter and collector of Q2 of PNP are reversed.

2. The base of both transistors should be connected in series with current limiting resistor.


3. The power supply VDD is only 1.5V, even the lighting threshold of the light emitting tube is not enough, even if the circuit is correct, it will not light.

0
user image

Louis Posté sur July 1, 2020

Transistor Q2 has the wrong direction, the base current is not available, and it is impossible to conduct. The voltage output by U4 is also clamped by the emitter of Q1 and cannot be higher than 0.7V. You have to consider this circuit carefully.

0
  • Elias

    Elias Posté sur July 1, 2020

    Ok brother

  • Vous devez vous connecter pour répondre. Se connecter | Registre

Écrivez une réponse

Vous devez vous connecter pour répondre. Se connecter | Registre