# Current regulator **URL:** \ **Category:** General Electronics\ **Created:** [April 1, 2024, 10:21pm UTC](https://forum.arduino.cc/t/current-regulator/1242738 "2024-04-01T22:21:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![MasoudHasany](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/masoudhasany/32/1098565_2.png) [@MasoudHasany](https://forum.arduino.cc/u/MasoudHasany)\ **Post date:** [April 1, 2024, 10:21pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/1 "2024-04-01T22:21:52Z")
Hello everyone, Is there any built-in component that can regulate the output current to as low as 0.5 mA when the input is 6 V and 1 A? Thanks ---
**Author:** ![cedarlakeinstruments](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/cedarlakeinstruments/32/1128931_2.png) [@cedarlakeinstruments](https://forum.arduino.cc/u/cedarlakeinstruments)\ **Post date:** [April 1, 2024, 10:31pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/2 "2024-04-01T22:31:38Z")
You may have to look for a low-dropout regulator, but the idea is still the same. 7805 voltage regulator can be connected as a current regulator. > What do you mean by 'built-in'? Do you mean built into the arduino? ---
**Author:** ![Grumpy\_Mike](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/grumpy_mike/32/213521_2.png) [@Grumpy\_Mike](https://forum.arduino.cc/u/Grumpy_Mike)\ **Post date:** [April 1, 2024, 10:37pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/3 "2024-04-01T22:37:51Z")
Moved your post to here as you posted in a section whose description says do not post here. ---
**Author:** ![Grumpy\_Mike](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/grumpy_mike/32/213521_2.png) [@Grumpy\_Mike](https://forum.arduino.cc/u/Grumpy_Mike)\ **Post date:** [April 1, 2024, 10:43pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/4 "2024-04-01T22:43:24Z")
> [@MasoudHasany](#): > > Is there any built-in component that can regulate the output current to as low as 0.5 mA when the input is 6 V and 1 A No. For a start 1A is only the maximum possible current a supply could supply. What is does supply depends on the load the voltage is driving. But more than that it illustrates that you do not know how electricity works. So tell us what you want to do this for and we will be able to offer practical advice on how to do what you want to do. ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [April 2, 2024, 12:56am UTC](https://forum.arduino.cc/t/current-regulator/1242738/5 "2024-04-02T00:56:40Z")
Hi, @MasoudHasany > [@MasoudHasany](#): > > Is there any built-in component that can regulate the output current to as low as 0.5 mA when the input is 6 V and 1 A? What is the application? Why do you need variable current output? Thanks.. Tom.. 😀 👍 ☕ 🇦🇺 ---
**Author:** ![MasoudHasany](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/masoudhasany/32/1098565_2.png) [@MasoudHasany](https://forum.arduino.cc/u/MasoudHasany)\ **Post date:** [April 2, 2024, 8:00am UTC](https://forum.arduino.cc/t/current-regulator/1242738/6 "2024-04-02T08:00:25Z")
Hello, Thanks all. Here is the application: In my design, I have a supercapacitor that should be charged with a solar panel (6 V output). The charging current must not exceed 0.5 or 1 mAmp. BR Masoud ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [April 2, 2024, 8:14am UTC](https://forum.arduino.cc/t/current-regulator/1242738/7 "2024-04-02T08:14:10Z")
Hi, @MasoudHasany > [@MasoudHasany](#): > > The charging current must not exceed 0.5 or 1 mAmp. Why do you need to limit the charge current? How big is the PV, Watts? Thanks.. Tom.. 😀 👍 ☕ 🇦🇺 ---
**Author:** ![MasoudHasany](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/masoudhasany/32/1098565_2.png) [@MasoudHasany](https://forum.arduino.cc/u/MasoudHasany)\ **Post date:** [April 2, 2024, 8:31am UTC](https://forum.arduino.cc/t/current-regulator/1242738/9 "2024-04-02T08:31:55Z")
Hi Tom, Because it is related to the design of the supercapacitor. When the current is not limited, the IR drop is a lot. I want to limit that. ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [April 2, 2024, 9:21am UTC](https://forum.arduino.cc/t/current-regulator/1242738/10 "2024-04-02T09:21:57Z")
Hi, @MasoudHasany > [@MasoudHasany](#): > > When the current is not limited, the IR drop is a lot. I want to limit that. What do you mean by "IR"? Tom... 😀 👍 ☕ 🇦🇺 ---
**Author:** ![MasoudHasany](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/masoudhasany/32/1098565_2.png) [@MasoudHasany](https://forum.arduino.cc/u/MasoudHasany)\ **Post date:** [April 2, 2024, 10:35am UTC](https://forum.arduino.cc/t/current-regulator/1242738/11 "2024-04-02T10:35:42Z")
[https://www.google.com/search?q=ir+drop&rlz=1C1KNTJ\_enDK1036DK1036&oq=IR+drop&gs\_lcrp=EgZjaHJvbWUqBwgAEAAYgAQyBwgAEAAYgAQyBwgBEAAYgAQyBwgCEAAYgAQyBwgDEAAYgAQyBwgEEAAYgAQyBwgFEAAYgAQyBwgGEAAYgAQyBwgHEAAYgAQyBwgIEAAYgAQyBwgJEAAYgATSAQgxOTY3ajBqMagCALACAA&sourceid=chrome&ie=UTF-8](https://www.google.com/search?q=ir+drop&rlz=1C1KNTJ_enDK1036DK1036&oq=IR+drop&gs_lcrp=EgZjaHJvbWUqBwgAEAAYgAQyBwgAEAAYgAQyBwgBEAAYgAQyBwgCEAAYgAQyBwgDEAAYgAQyBwgEEAAYgAQyBwgFEAAYgAQyBwgGEAAYgAQyBwgHEAAYgAQyBwgIEAAYgAQyBwgJEAAYgATSAQgxOTY3ajBqMagCALACAA&sourceid=chrome&ie=UTF-8) ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [April 2, 2024, 11:32am UTC](https://forum.arduino.cc/t/current-regulator/1242738/12 "2024-04-02T11:32:41Z")
Hi, How big is your PV in watts? What is its short circuit current? Will you have a blocking diode to stop the capacitor discharging back into the PV when its output goes down in the dark? What gauge wire are you using to connect the PV to capacitor and how long? How much IR drop are you expecting/measured? Thanks.. Tom.. 😀 👍 ☕ 🇦🇺 ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [April 2, 2024, 12:23pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/13 "2024-04-02T12:23:12Z")
> [@MasoudHasany](#): > > Is there any built-in component that can regulate the output current to as low as 0.5 mA when the input is 6 V and 1 A? No. Is there any reason you can't just use a resistor? ---
**Author:** ![MasoudHasany](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/masoudhasany/32/1098565_2.png) [@MasoudHasany](https://forum.arduino.cc/u/MasoudHasany)\ **Post date:** [April 2, 2024, 2:23pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/14 "2024-04-02T14:23:01Z")
How is that possible when the voltage of the supercapacitor is changing during charging? Can you explain more? ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [April 2, 2024, 2:29pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/15 "2024-04-02T14:29:55Z")
So I guess using a resistor to limit the current is out. It easy and simple. OK, just a suggestion ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [April 2, 2024, 2:42pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/16 "2024-04-02T14:42:07Z")
> [@MasoudHasany](#): > > How is that possible when the voltage of the supercapacitor is changing during charging? Can you explain more? Google; > How a capacitor works You will be surprised. With no charge on a capacitor, there is no voltage on the capacitor. As you charge the capacitor, the potential difference across the capacitor, the voltage, increases from zero. Please answer; > [@TomGeorge](#): > > How big is your PV in watts? > What is its short circuit current? > Will you have a blocking diode to stop the capacitor discharging back into the PV when its output goes down in the dark? > > What gauge wire are you using to connect the PV to capacitor and how long? > > How much IR drop are you expecting/measured? Tom.. 😀 👍 ☕ 🇦🇺 ---
**Author:** ![MasoudHasany](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/masoudhasany/32/1098565_2.png) [@MasoudHasany](https://forum.arduino.cc/u/MasoudHasany)\ **Post date:** [April 2, 2024, 2:44pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/17 "2024-04-02T14:44:32Z")
Hi, 1. It gives 120 mA as the max output. Considering that the voltage is 6 V, it is 720 mA. 2. It depends on the light intensity. Am I wrong? 3. Yes, I have. 4. 28G. 5. It totally depends on the charging rate. We want to keep it as low as possible. That is why I need to limit the current to not more than 0.5 mA. BR Masoud ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [April 2, 2024, 2:50pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/18 "2024-04-02T14:50:34Z")
> [@MasoudHasany](#): > > It gives 120 mA as the max output. Considering that the voltage is 6 V, it is 720 mA. What does that mean? How do you get 720mA? If the short circuit current is 120mA, then that is the maximum current you will get from the PV. Have you calculated the volt drop across your 28g wire at 120mA? Have you used Ohms Law? What is the resistance of your length of 28g connecting wire? I think you are OVER THINKING your project and need to do some more research. PLEASE draw a simple schematic of your proposed circuit. How big is the supercap? Thanks.. Tom.. 😀 👍 ☕ 🇦🇺 ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [April 2, 2024, 3:06pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/19 "2024-04-02T15:06:05Z")
If you don't want to use a resistor, you could use a current regulating diode. ---
**Author:** ![MasoudHasany](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/masoudhasany/32/1098565_2.png) [@MasoudHasany](https://forum.arduino.cc/u/MasoudHasany)\ **Post date:** [April 2, 2024, 4:10pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/20 "2024-04-02T16:10:45Z")
Thanks. Something like this: [https://eu.mouser.com/ProductDetail/Semitec/S-501T?qs=wgO0AD0o1vsrGXznDcjjCw%3D%3D](https://eu.mouser.com/ProductDetail/Semitec/S-501T?qs=wgO0AD0o1vsrGXznDcjjCw%3D%3D) ---
**Author:** ![jim-p](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/jim-p/32/922840_2.png) [@jim-p](https://forum.arduino.cc/u/jim-p)\ **Post date:** [April 2, 2024, 4:17pm UTC](https://forum.arduino.cc/t/current-regulator/1242738/21 "2024-04-02T16:17:30Z")
Yes but you must realize that it will only provide a constant current while the voltage difference between the source voltage and the capacitor voltage is greater than 1.1V, below that, it basically acts as a resistor [Next page](https://forum.arduino.cc/t/current-regulator/1242738.md?page=2)