i need help with my monostable circuit!!

[GromTag]

Then the Transistor is showing fault.

Do you have a datasheet for that specific 555IC?

 

[GromTag]

If that 555Ic can handle up to 200mA source/sink, then directly wired to the relay would be consuming up to 127.5mA at 9 volts, near its max capability, if that particular chip can handle that.

 

[toh liu wang]

Alright i will get it changed soon. I do not have datasheet for that 555Ic

 

[GromTag]

hmm, many have made those chips, some can be different current rating for what they can handle in terms of current, tho many are rated at 200mA max.

 

[toh liu wang]

When i wire it directly to the relay, the motor spins without pressing the button switch.

 

[toh liu wang]

I think i have a few different 555ics with me

 

[toh liu wang]

Maybe its the relay? like the wires are in wrong order?

 

[GromTag]

then the IC may be jammed on sinking, it may have been so the entire time, process of elimination for finding faults in any circuit unless directly known, is of coarse not simple.

The Source/Sink (Push/Pull) stage may be damage in the IC. Or the control stage for the internal switch may not be functioning correctly.

 

[toh liu wang]

I've already changed a new ic.

 

[toh liu wang]

i'll change the button switch too

 

[toh liu wang]

Motor still runs without even pressing the switch.

 

[toh liu wang]

Is it actually possible to let a monostable circuit turn off my motor? Or it actually doesn't work that way?

 

[toh liu wang]

i've done it once before, the motor spins for 30 seconds and then it stops. After that, it couldn't work anymore

 

[GromTag]

A monostable can accomplish this, I am in the process of acquiring some to control timing of Photo Triacs to switch AC.

Something is with that relay.

 

[toh liu wang]

The relay clicks when there is power supply but it either wont turn the motor off or wont let it stay on

 

[GromTag]

It's 3:20 A.M. I'm getting why did I not think of that moments....

The 555 IC does go High/Source when switched on, running on the resistor capacitor timer, the chip sinks at all other times (Off), when pin 3 is directly connected to the relay, the 555 IC will keep the relay on at all times, sinking the relay, and when the 555IC is switched on the relay is now getting positive at both poles, all tho not completely so, the 555IC does not fully supply rail voltage, the relay being a sensitive coil type by the datasheet for that model number can cause odd results with the IC.

 

[toh liu wang]

Sorry for troubling you! I need to get another type of relay that will work well with the ic?

 

[GromTag]

No, no no trouble,

The relay, all be it a bit low for your voltage, the coil is rated again at 5V 70 -71 mA, and at again 9v it allows 127 agv mA, the coil can get rather warm with this,

to get the IC to drive that relay, the IC would have to be the power sender, meaning the pin 3 becomes the positive supply.

Pin 3 would need to be the relays positive, then the other end of the coil directly to the common GND to power supply, however the flyback diode now needs to be placed at the pin 3 to relay point then directly to the power supply positive.

Recap. 555IC pin 3 to relays chosen positive, relays chosen negative to main power common, flyback diode annode to the pin 3 relay connection, Cathode to the main supply positive.

 

[GromTag]

Overall, this would put strain on the 555IC.

 

[toh liu wang]

i'm sorry, i don't really get it... For now i do not need the transistor and resistor?