Experiments 4.1 : Applications - The 555 Timer Sequence

[lolypopboy777]

Thanx! worked in first try! :D

(NE 555 99144)

[fabiuh991]

Hi, can you explain something to me, it has nothing to do with this vid, but with electronics in general..

How can the mains voltage be stepped down only with resistors and capacitors? voltage divider? that type of circuit can only be used with very low power draw right?

I have a regular comercial motion sensor, it has 2 boards inside, the PIR circuit and the power/relay board. It takes the 220v and must reduce it in order for the remaining circuit to work.. How is this done?

Thanks! =)

[robert327janes]

@fabiuh991 if the motion sensor actually works off of 220vac i would be surprised. generally most electronics convert ac mains to dc through a step down transformer and rectifier circuit ( how efficient the power supply is up to your design ) you are going to need the step down transformer, diodes, caps, resistors and voltage regulator at the very least to have a decent supply. your power board on your sensor probably uses a switching regulator, though; more than i can get into here.

[fabiansdesigns]

Que pena ese tarnsistor Que esta junta ala resistencia se utiliza para controlar el voltaje de la bateria

GRAcias

[DerekMolloyDCU]

@deeaks Yes, I calculate it on the webpage attached to this video. See the link on the DerekMolloyDCU Channel homepage (no urls are allowed in comments)

[deeaks1]

is there a link to the lecture where you calculated all the component values? i would be interested to know.

[lenny7494]

Almost 1300 views and 1 LIKE!?!?! Come on People!!!