I recently purchased two Pololu 5V Step-Up Voltage Regulator U1V10F5.
I wanted to use this to power an Arduino from a 5.5V supercaps.
The issue is that I cannot get more than 40mA @ 5V on the output side.
Here is my setting:
On a breadboard, I have 33uF electrolytic caps located before Vin and GND.
With a power supply (current limit to 1.2A), I put in 5V on the input.
On the output side, I tried different resistors to test its performance under load.
I started of with 1k down to 100 ohm. Everything seemed fine, until I placed the 100 ohm load.
Once I put 100 ohm on Vout, the regulator starts drawing more than 1.2A and hits the current
limit on the power supply. This made no sense to me.
According to the efficiency chart, let’s say the worst case efficiency = 0.7
Then VoutIout = effVin*Iin. Solving for Iout when Iin is at its max (1.2) and Vout = Vin = 5V, Iout should be
around 840mA.
I also tried the second part in case the first one was a defect. But with the same exact setup,
it shows the same exact result.
Am I not understanding something here? I feel like I am missing some key concept.
Thank you for your help.
Figure 1. Power supply voltage and current limit
Figure 2. Front side of the setup
Figure 3. Back side of the setup
Figure 4. Voltage drop across the load
Figure 5. Power supply when turned on