K2599 Velleman Kit - Intermittant Wiper - assembly issue

Kits Automotive projects
#1

Hello all.,

Had no issue on assembly of kit, very familiar with soldering and electronic boards.

After assembly , during bench testing, the device worked beautifully for about 10-15 mins.

Then suddenly stopped working. No relays activate - only Red LED illuminates upon applying voltage.

No change when timer delay selector is rotated.

Any ideas ? Did the Timer IC go bad ?

Before powering for 1st time, all solder connections were double checked.

After failure, chk’d again, no indication of anything out of order or mis-installed.

Thanks !

#2

Electronics just don’t go bad overnight. There must be a reason for it. Something must have changed.
Maybe there is a mechanical cause (bad/loose soldering(s), crack in track or pad, …)

#3

Ebay seller of the item sent me just a replacement of the IC555 and its working again beautifully.

#4

Still there must be a reason for the IC to go bad.
Spike on the power supply? Static? Inverse polarisation?

#5

no clue. was working, stopped, replaced IC working again.

Tech question:

what component would i swap out to adjust the timing ?
Could a Potentiometer be used to adjust the timing of the delay ?

Want wiper to make one full sweep and then park.
project calls for a fast sweep and a slow park, so I intend to use a voltage pot on the park lead.
but may need to control the timing of how long power needs to be applied to the motor’s fast lead for a full one direction sweep…

thank you

#6

R1, R2, R3 determine timing.
You could replace one of them with a trimmer.
Sorry, no values, please experiment.
Please see diagram.

#7

Hello, do you know if the Velleman K2599 can be used with a positive earth car?