Hello,
Yesterday i bought the Fan Timer K8041. According the spec’s you can set the time from 5sec to 5min. When i tested it i could only reach a maximum time of 2,5min. This is not correct according the spec’s. I need at least a 5min delay for my purpose. Now i read on this forum that it is not possible to extend the time, because then the timer will be unstable. My question to Velleman is, you are selling a product that not meets the spec’s you are writing down on the website. How is that possible? Or can you give me a reason why my fan Timer can not reach the 5minutes delay. There must be a way to change the value of the components i think. I can do that by myself but you must help. At this moment the Fan Timer is useless for me, because i get the wrong information about the spec’s. I hope you have a solution.
[quote=“fgeer”]Hello,
Yesterday i bought the Fan Timer K8041. According the spec’s you can set the time from 5sec to 5min. When i tested it i could only reach a maximum time of 2,5min. This is not correct according the spec’s. I need at least a 5min delay for my purpose. Now i read on this forum that it is not possible to extend the time, because then the timer will be unstable. My question to Velleman is, you are selling a product that not meets the spec’s you are writing down on the website. How is that possible? Or can you give me a reason why my fan Timer can not reach the 5minutes delay. There must be a way to change the value of the components i think. I can do that by myself but you must help. At this moment the Fan Timer is useless for me, because i get the wrong information about the spec’s. I hope you have a solution.
Thanks.[/quote]
Hello again,
I found by myself the solution to reach a delay time to 5min. The biggest problem was that the electrolitic capacitor C5 was made of a very poor quality or it was a very old one. It has very bad specifications (leak). So i changed this Elco to a good quality type and also i doubled the capacity to 470uF. I also changed resistor R5 from 100K to 1M. Please no more then 1M when you replace R5. The consequents of my changes are that the minimum time is raised to 1.10 minutes. But the maximum time is now 5 minutes. That is what i wanted. I must say, that Velleman must redesign this kit, because it’s not according the spec’s they are saying. I hope this will help other kit buiders to solve the time problem. Thanks.
Hello, I have the same problem and apparently finds Velleman Europe todate
it is not necessary to adjust/to solve this or to respond.
There I have a fan with two speeds, I would like to connect a relay instead of fan on sk2 Terminal block.
Is this possible?
I have a relay coil voltage 220v ~ with four Exchange contacts. I would like to disable the fan on high speed to run at least 5 min.
If I were a lamp 30W connects to the sk2 Terminal block, then it works when I’m on the sk1 Terminal block L and Lx connects for 4 minutes.
I hang the relay on the Terminal block, then it goes to idle relay cross-over point without L and Lx connects and interrupts not after 4 minutes.
Is there anyone who can help me or have I bought the wrong kit?
Incidentally, I have the values of the R5 and C5 according to your advice changed.
Sorry, we’d like to help but we have troubles understanding your post.
Can you please clarify regarding the exact problem that you experience?
Please do not use Google translate, it sometimes gives strange results
It has been a long time from the last activity here but … my 8041 has also been idle for a year at least until now. When I discovered abovementioned issue with times not to specs then disappointment came in. Initially it was from 10 sec to 2,5 minutes and I was into making timer to run longer. After changing R5 to 1Mohm and C5 to 1000 uF it is now from 3 to 10 minutes and so far no signs of unstability or overheating issues. C5 is from Teapo.
There is misleading operation explanation in the manual though where it says that after Lx has been disconnected: “the fan will continue its operation for 5 more minutes. This delay can be adjusted by turning potentiometer RV1.” It doesn’t say that 5 minutes is projected maximum (it doesn’t do even that). Who on earth needs a fan controller that turns fan on for only 10 seconds?
Gotta find IR controlled outdoor light and modify it because I need on times up to 30 minutes …
Also my K8041 has a delay time which is much less than the promised 5 minutes.
Would one of the Velleman experts respond on the suggested timer solutions?
[quote=“acpb”]Also my K8041 has a delay time which is much less than the promised 5 minutes.
Would one of the Velleman experts respond on the suggested timer solutions?[/quote]
Hy, my user name on this forum is “dre”
The max. delay time for this 8041 kit is indeed arround 2.5 minutes.
Reason: When LX is switch off, the load on C5 is directly dicharging via R7 = 10K, BE from T3 and BE from T4 (in serial). Note: BE is Base and Emitter.
and a small limitation across R5 and RV1 wich was the inteb-ntion in this circuit.
The simply way what you can do is change the value R7 from 10k into 82K. The maximum delay
The maximum delay reach now approx. 5 minutes.
The potmeter RV1 works lineair from minimum position to the mid-position (3 minutes) and logarithmyc from mid-position to the maximum position (+/- 5 minutes.
Normally it,s works directly with R7 = 82K. If the circuit is a little bit unstable then you can change T3 /T4 into BC547C type,s i.s.o B type,s.
I buy a new one now and I will change T3 an T4 into a N-channel FET wich input impedance becomes very higher.
I think I can go to simply 10 minutes of even more …
I will tell this later becease I found not the time to do it.
grtn,
dre
