I have a Samsung Travel Adapter,
Input: 100-240 V - 50-60 Hz 0.50 A
Output: 9.0V --- 1.67 A or 5.0 V---2.0A
(Adaptive fast charging)
Can I use this safely with my raspberry pi? If not, can anyone give me suggestions from amazon?
FWIW, I've measured the behaviour of a similar device: Samsung EP-TA20UWE:
http://www.cpmspectrepi.uk/raspberry_pi ... EP-TA20UWE
Whilst, at the currents I was testing with, all voltages were <5V, it was unclear as what actually triggers the "Adaptive fast charging" and, presumably, 9V, but the voltage was beginning to "rise back up" after ~650mA so I wouldn't trust it to power a Pi safely!. Whilst I would always recommend an "official power supply"** some of the better behaved ones shown elsewhere in the above web page have been bought via amazon and used with (older) Pi's.
** I have one of the original, pre-P3B, white versions: http://www.cpmspectrepi.uk/raspberry_pi ... _Models.29
Still running Raspbian Jessie on some older Pi's (an A, B1, B2, B+, P2B, 3xP0, P0W) but Stretch on my 2xP3A+, P3B+, P3B, B+, A+ and a B2. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm